Technology Today HIG HL IG HTI N G RAYTHE ON’S T ECH NOLOGY 2014 ISSUE 1 Raytheon Research Developing Tomorrow’s Technology Today A MESSAGE FROM Mark E. Russell Vice President of Engineering, Technology and Mission Assurance Raytheon has always valued a focused research portfolio that both continuously improves our products and offers revolutionary new capabilities. Best performing, affordable solutions are important in today’s fiscally constrained environment, and Raytheon’s research provides a mechanism to identify and nurture technologies that help develop best-in-class solutions. Raytheon’s research approach is multifaceted where Raytheon laboratories enterprisewide perform research that impacts our core sensing, effects, C3I (command, control, communications and intelligence), mission support and cyber markets. Collaboration and partnerships with universities, small businesses and other contractors are critical elements of our approach. As part of a formal process, research topics and results from across the company are integrated and continuously assessed against Raytheon products and customer mission needs to ensure focus on the most promising and needed areas. This issue highlights the depth and breadth of Raytheon research, including our more than 30-year commitment to multifunction, wideband and high-power active electronically scanned array (AESA) technologies and longer range research areas including quantum computers. While it may take years to realize the benefits in a particular area, conducting research is nonetheless a critical part of maintaining excellence for our future products. Our development of gallium nitride semiconductor device technology began nearly 15 years ago and today provides the foundation for our most advanced radar, communication and electronic warfare development programs. In our Leaders Corner, Raytheon Chief Technology Officer Bill Kiczuk and the other Technology Leadership Council members discuss their roles as technology leaders and how Raytheon collaborates and nurtures research across the company. In our Eye on Technology section, Raytheon Australia’s sapphire resonator oscillator technology, developed by recently acquired Poseidon Scientific Instruments, is presented. Our special interest section highlights two of Raytheon’s university partnerships; our partnership with the Franklin W. Olin College of Engineering, where a team of engineering students work for a year with Raytheon engineers on real-world engineering projects, and our collaboration with Worcester Polytechnic Institute that includes science, technology, engineering and mathematics (STEM) education, course development and research. On the cover: The Raytheon BBN Technologies quantum computing lab where employee Colm Ryan analyzes results from a recent experiment. 2 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Mark E. Russell View Technology Today online at: www.raytheon.com/technology_today INSIDE THIS ISSUE Feature: Research Technology Today is published by the Office of Engineering, Technology and Mission Assurance. Vice President Mark E. Russell Chief Technology Officer Bill Kiczuk Raytheon Research: Delivering Discriminating Technologies 4 Raytheon AESA Research: Past, Present and Future 8 State-of-the-art RF Semiconductors for Military Systems 14 Computational Imaging Technology 18 BareMetal: a New Cybersecurity Technology 21 Next Generation EO/IR Detectors 22 Quantum Computers: Big and Small 24 Particle Flow Filters to Solve Near Impossible Problems 28 Automated Language Translation 30 Managing Editor Tony Pandiscio Optimization Algorithms for Decentralized Planning and Control 32 Feature Editor John Zolper Partially Observable Decision Processes 36 Senior Editors Corey Daniels Eve Hofert Art Director Susan DeCrosta Photography and Art Fran Brophy Stephen Delisle Daniel Plumpton Website Design Nick Miller Publication Distribution Rose McGovern Contributors Paul Bailey Steve Klepper Tony Marinilli Lindley Specht Nora Tgavalekos Raytheon Leaders Corner Q & A With the Raytheon Technology Leadership Council 40 Eye on Technology Raytheon Australia’s Poseidon Scientific Instruments 42 Special Interest Raytheon’s Collaboration With Worcester Polytechnic Institute 44 Raytheon’s Partnership With the Franklin W. Olin College of Engineering 46 Patents 48 RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 3 FEATURE Raytheon Research: DELIVERING DISCRIMINATING TECHNOLOGIES Raytheon is a leading technology and innovation company that consistently provides innovative solutions, services and mission support to our global customers. Our vision is to be the most admired defense and aerospace systems company through our worldclass people, innovation and technology. T o achieve this vision, Raytheon maintains a leadership position in the technologies that enable our products to deliver mission solutions. A robust, diverse research portfolio is essential to our strategy. Raytheon research is not solely an internally focused activity done in a central corporate laboratory. Rather, Raytheon research is a highly dynamic, collaborative process where good ideas and novel solutions come from many sources. Raytheon has developed a well-structured, mission-to-technology assessment process to identify technology areas whose development will yield new or enhanced products and system capabilities. The process starts with customer roadmaps and mission requirement documents plus Raytheon’s deep domain knowledge, and drives down to identifying the critical enabling technologies. Synergies are identified across product families (e.g., core technologies for multiple radars) to leverage our research investments. Technology development can be achieved via various project and funding mechanisms, including customer program-funded technology development, customer contracted research and development (CRAD), independent research and development (IRAD), partnerships and alliances that include universities, small businesses and 4 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY government laboratories and mergers and acquisitions. This approach leads to a research and technology portfolio that leverages expertise both within Raytheon and externally. chains enables Raytheon to identify technology needs and opportunities, and to focus research and development to best meet the end customer’s system requirements. An important part of Raytheon’s research portfolio is the in-house development and application of advanced semiconductor devices. Figure 1 is an electro-optical/infrared (EO/IR) example of Raytheon’s continuum of technology development, which spans materials, devices, modules, systems and platforms. The figure includes images of an EO/IR system evolution that starts with a mercury cadmium telluride (HgCdTe) crystal boule, progressing to wafers fabricated with EO/IR focal plane arrays (FPAs), to the formation of complete detector modules, to the integration of imaging subsystems, and finally to integraton on host platforms. Raytheon also has a completely integrated radio frequency (RF) roadmap, extending from semiconductor monolithic microwave integrated circuits (MMICs), to transmit/receive modules, to active arrays and ultimately to full radars. The deep domain knowledge across these integrated technology Sensor and Device Technologies The article by Sarcione et al., “Raytheon AESA Research: Past, Present and Future,” presents Raytheon’s more than 40 year history developing and productizing multifunction, wideband and high-power active electronically scanned array (AESA) technologies. AESA technologies have progressed significantly during the past four decades at Raytheon, and our research progress provides our domestic and international customers with advanced unprecedented capabilities and performance. Applications span surface, space and airborne platforms for radar, communications and electronic warfare missions and the article highlights key past, present and potential future technology advances in areas such as MMICs, low noise RF sources and packaging. Complementing the AESA article, the article by Whelan et al., “State-of-the-art RF PLATFORMS SYSTEMS MODULES DEVICES MATERIALS Figure 1. Representation of electro-optical/infrared (EO/IR) technology progression from materials to platforms. The images are for EO/IR focal plane array (FPA) technology going from mercury cadmium telluride (HgCdTe) crystal boules, to FPA wafers, to complete detectors, to imaging subsystems integrated on platforms. FEATURE Semiconductors for Military Systems,” reports on recent progress in developing, maturing and applying high-performance MMICs to an array of Raytheon products. The article covers low-noise metamorphic high electron mobility transistors (mHEMTs) for RF receivers as well as high-power gallium nitride (GaN) MMICs that are critical enablers for new Department of Defense (DoD) systems. As noted in the article, the Office of the Secretary of Defense (OSD) honored Raytheon in 2013 for successful completion of a Defense Production Act (DPA) Title III GaN production improvement program that culminated in the demonstration of a manufacturing readiness level (MRL1) of 8 for the GaN MMIC technology. This is the first MRL 8 certification of GaN MMICs in the industry and indicates a readiness to enter low rate initial production. The article by Johnson and Smith, “Next Generation EO/IR Detectors,” reports on recent progress in several EO/IR detector technologies that enable increases in image resolution, target discrimination and reduced system cost. The first area covered is the emerging field of strain-layer superlattice high operating temperature mid-wave IR detectors having fundamental properties that in theory perform better than HgCdTe and can cost less by leveraging the III–V semiconductor manufacturing infrastructure. Also described are dual-band mid-wave/long-wave detectors that afford superior target discrimination because of the distinct image spectral characteristics of the two bands. Finally, progress in uncooled microbolometer technology is presented with the successful realization of a 2048 x 1536 pixel long-wave FPA that is the world’s largest uncooled sensor of this type. Dramatic improvements in image resolution are reported for this uncooled FPA. The article by Gann and Gibbons, “Computational Imaging Technology is Revolutionizing Digital Imaging,” discusses an additional path Raytheon has explored to further improve sensor imaging systems, i.e., Figure 2. One of the quantum computer research areas at the Raytheon BBN Technologies Bits and Waves lab. The suspended cylinder to the left is a dilution refrigerator used to cool the quantum computing devices to an operating temperature below 50 milli-Kelvin. computational imaging (CI). CI leverages advances in digital processing along with novel algorithms and sensor architectures to enable new strategies for optimizing imaging systems. The essence of computational imaging is the idea that significant gains can be attained by inserting the computational step earlier in the image acquisition or formation chain — not just performing processing post-image formation — to produce improved and specialized forms of scene information. Raytheon has been collaborating with several universities and small businesses in this field. The final sensor and device technology article, “Quantum Computers: Big and Small,” describes one of Raytheon’s farthest reaching research areas: quantum computers. The promise of quantum computers to provide exponentially faster computation, compared to conventional computers, has been widely touted. But while the “physics works ” for a very select set of problems, some of which 1 MRL is a measure used by the DoD and many of the world’s major companies to assess the maturity of manufacturing readiness. are of high interest to Raytheon’s customers, the computer engineering to produce a truly robust large-scale computer remains a research topic. The authors of this paper, Dutton and Silvia, are from the Quantum Information Processing (QuIP) group at Raytheon BBN Technologies, a recognized leader in quantum computer technologies. The authors report on the status of their quantum computing research, highlighting their progress in extending the de-coherence time of their superconducting quantum bit (qubit) and achieving logical, versus physical, qubits such as are required for computationally useful quantum computers. Their research is conducted at the BBN Bits and Waves laboratory in Cambridge, Mass. (Figure 2). Algorithms and Processing The previous section discusses research in CARCO Rate table supplied by Ideal Aerosmith, LLC. sensor and device technology, but in many of Raytheon’s systems, backend algorithms and processing also play a crucial role. RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 5 FEATURE Advancements in mathematics, as well as algorithmic strategies and progress in digital processing, are exploited to more effectively and more efficiently turn sensor data into actionable information. The end-system solution must trade off computational precision and accuracy with the execution speed and power requirements. A highly accurate solution that is achieved only after mission completion has little value; nor is a solution useful that requires more computational power than the platform can provide. The first article in this area, “Particle Flow Filters to Solve Near Impossible Problems” by Daum, represents a significant advance in the use of particle filters to efficiently calculate high-accuracy estimates of nonlinear system states such as a ballistic missile’s position and velocity. Prior to this work, particle filters were known to be highly accurate but required extensive computational resources in run time and processor capability such that they were not viable for most real-time applications. Daum invented a new variant of the particle filter, the particle flow filter (PFF), and his solution is orders-of-magnitude computationally faster than standard particle filters. The key improvement is a new way to select the particle locations based on the underlying physics describing the system’s dynamics. For some applications, a speed increase of 10 orders of magnitude over conventional particle filters is achieved with an estimation accuracy superior to the widely used extended Kalman filter. These results could have wide-ranging impacts on a broad range of Raytheon products. Effective automated language translation (ALT) capabilities are needed more than ever, primarily because of the massive amount of data available on the Internet, half the content of which is in languages other than English. Raytheon BBN Technologies has been researching automated language translation for over a decade, and the article by Abib, Makhoul and Andrews, “Automated Language Translation,” presents groundbreaking work on ALT with their statistical machine translation (SMT) approach. Instead of defining translation rules manually, SMT uses a machine learning approach to develop a large set of translation rules automatically based on statistical models of translation. SMT has 6 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Raytheon Research: Delivering Discriminating Technologies revolutionized automated language translation by quickly and cheaply enabling the development of translation systems for new languages and domains. Raytheon BBN Technologies has developed and matured the SMT approach under several Defense Advanced Research Projects Agency (DARPA) initiatives, including the Global Automatic Language Exploitation (GALE) program and the Translation for Tactical Use (TransTac) program. They have also created several turnkey solutions for both the government and commercial markets based on their translation technology. A new Raytheon Pikewerks product called BareMetal is highlighted in the article “BareMetal: A New Cybersecurity Technology” by Fraser, Tanen and Egalite. BareMetal is a small, portable device that allows an information technology (IT) professional (not necessarily a firmware expert) to quickly characterize the firmware on their IT systems and identify potential threats. IT equipment uses firmware to load the operating system and initialize system components. Firmware is evolving from the basic input/output system (BIOS) type used extensively in the past to new firmware based on the Unified Extensible Firmware Interface (UEFI) standard. Although this standard enables more structured and efficient firmware development, it also potentially introduces new opportunities for adversaries to inject low-level malware and low-level vulnerabilities. Most IT equipment security products monitor and protect the application software, but BareMetal specifically focuses on threats to the low-level firmware where some of the most persistent and hidden malware can hide. Figure 3. A simulated urban area is used to test and refine cooperative unmanned aerial vehicle control algorithms that optimize the ability to find and track ground objects of interest. FEATURE Autonomous Systems Autonomy relates to systems which have a set of intelligence-based capabilities that allow them to respond to situations that were not preprogrammed or anticipated in the design. Autonomous missions are typically conducted in unstructured and dynamic environments where the systems must have a degree of self-governance and adaptability. In 2011, OSD identified seven science and technology area priorities that they would invest in from 2013 to 2017. These technologies are expected to greatly impact future OSD systems and mission needs. One of these technology areas is autonomy. In response to this need, Raytheon formed a cross-company team of subject matter experts in fields related to autonomy to develop key enabling technologies in this area and a strategy for their application to Raytheon products. Two articles that describe autonomy-enabling decision and control frameworks are included in this research edition. The first article, “Optimization Algorithms for Decentralized Planning and Control ” by Hirsch and Schroeder, presents research on optimization algorithms for distributed planning and control. This work supports our customer’s goal of doing more with less. Specifically, there is interest in having multiple unmanned aerial vehicles (UAVs) be controlled by a single operator. This entails a more distributed and autonomous control of some UAV functions versus the current centralized operator-intensive control. Hirsch and Schroeder describe their approach to this problem as a hybrid methodology combining greedy randomized adaptive search procedures (GRASP) and simulated annealing (SA). Their approach has been tested in simulation using a scenario that contains multiple UAVs searching for multiple targets in an urban area (Figure 3), and a summary of their results is presented. The second article, “Partially Observable Decision Processes” by Moore and Vitali, presents an analytic framework for making decisions based on only a partial understanding of a situation, i.e., partial information of the system state. The framework is based on the theory of partially observable Markov decision processes (POMDPs) and uses a belief state to quantify the uncertainty in the estimate of a system’s true state. Once calculated, the belief state is used to select the best course of action (COA) at that time. The article describes several application areas for the framework, including autonomous sensor control for conducting intelligence, surveillance and reconnaissance (ISR) missions and autonomous COA generation for an airport security monitoring system. Other Research at Raytheon Research and technology maturation continue to play critical roles at Raytheon in developing the best products to meet our customers’ mission needs. This issue of Technology Today highlights some of our current research projects in the areas of sensor and device technologies, algorithms and processing, and autonomous systems. There are many other projects ongoing in these areas and in other areas, all with the common goal of helping Raytheon maintain its ability to provide best value solutions to our customers. • John C. Zolper, Ph.D. ENGINEERING PROFILE John Zolper, Ph.D. Vice President, Research and Innovation John C. Zolper is vice president of research and innovation for Raytheon Engineering, Technology and Mission Assurance (ET&MA). He joined Raytheon in 2007 as part of the corporate technology team. Zolper partners with the chief technology officer to develop and implement an integrated technology and research vision and strategy for Raytheon. He leads the Raytheon Innovation Challenge to inspire creative solutions that address critical customer needs. Zolper points to the importance of his role of ensuring that “the company is constantly considering new and emerging customer needs by understanding customer capability gaps, assessing the technology available today and determining the technologies Raytheon should be developing for the future.” He spends a lot of his time “working to understand where customers are headed and what gaps they will have.” Prior to his position with Raytheon ET&MA, Zolper served in roles of increasing responsibility at the Defense Advanced Research Projects Agency (DARPA). As director of the Microsystems Technology Office (MTO), he was responsible for the strategic planning and execution of a portfolio of more than 75 research programs with an annual budget of more than $400 million covering all areas of advanced component technology, including electronics, photonics, MEMS (microelectromechanical systems), algorithms and component architectures. Before joining DARPA, Zolper was a program officer at the Office of Naval Research (ONR) and a principal member of the technical staff at Sandia National Laboratories. Zolper traces his path to Raytheon through his long involvement in high performance semiconductor technology, “I joined Sandia National Laboratories in 1989 where I applied my understanding of semiconductor materials and device technology to high performance electronics, performing early research on gallium nitride (GaN) transistors. In many ways, that work on GaN transistors led me to where I am today. I left Sandia to lead the wide bandgap semiconductor electronics programs at the ONR and then from there helped start the wide bandgap technology program at DARPA. That DARPA program was critical to establishing the viability of the GaN monolithic microwave integrated circuit technology that Raytheon is leveraging today in their designs.” RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 7 FEATURE RAYTHEON AESA RESEARCH: Past, Present and Future Introduction Multifunction, wideband and high-power active electronically scanned array (AESA) technology has progressed significantly during more than 40 years of development at Raytheon. The progress of our research provides domestic and international customers with unprecedented capabilities, performance and affordability. AESA applications span surface, space and airborne platforms for radar, communications and electronic warfare (EW) missions. The key technologies of monolithic microwave integrated circuits (MMICs), waveguide to printed circuit radiating elements, low noise sources, radio frequency (RF) and digital electronics, thermal and power conditioning, packaging, interconnects and processing continue to evolve and provide our customers with a wide range of solutions for their most challenging problems. The AESA has been, and will continue to be, the workhorse for the majority of RF sensors and other high-end RF systems. However, the evolution of RF packaging, device technologies and architectures continues to mold the AESA’s capability and affordability and their use is now extending beyond traditional military applications to include commercial weather and air traffic surveillance and wireless communication. Agencies such as the Department of Homeland Security (DHS), the Department of Commerce (DoC), the National Oceanic and Atmospheric Administration (NOAA), the National Weather Service (NWS), the Department of Transportation (DoT) and the Federal Aviation Administration (FAA) as well as the commercial wireless industry now also recognize the utility and cost-effectiveness of AESA-based sensor and communication systems. In addition, multifunction AESA-based systems are becoming more capable with dynamic transmit and receive functionalities that enable the same system to perform multiple missions. Looking at the evolution of AESAs from the early 1970s to today, we see a dramatic increase in capability enabled by key technology 8 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY developments in MMICs, radiating elements, receiver/exciters, beamforming and signal/data processing and packaging (Figure 1). The early focus was at the high frequency (HF) to ultraHF (UHF) bands, but today, AESAs operate from L-band through Ku-band and continue to extend into the millimeter-wave band, enabled by advances in gallium arsenide (GaAs), silicon (Si) and mixed signal devices. Gallium nitride (GaN), now in production at Raytheon, has enabled the next generation of higher power, more efficient AESA-based products. These technology developments enable architectures that provide cost and performance trades with scalability and modularity that are now more easily integrated into a wider variety of platforms and applications. The production of AESAs for many military applications and some high-end commercial applications (e.g., Iridium) began in earnest in the early 1990s. Packaging of the microwave electronic circuitry in most cases required hermetically sealed modules with corresponding interconnects, thermal control and a maintenance philosophy that dictated the weight, volume and maintainability of the AESAs. Today’s AESAs have evolved to become lighter, even with increased packaging density, while some still have hermetic packages, others exploit alternative environmental protection technologies. This evolution along with technology improvements in MMICs, interconnects, thermal control, etc., have realized a 50 percent savings in both weight and cost. The industry began investing in architectures and technologies several years ago to further improve the affordability and streamline the integration of phased arrays. The next generation of affordable AESAs are enabled by emerging MMIC technologies capable of supporting higher RF power per unit area (e.g., GaN), providing more functionality per unit area (e.g., RF complementary metal oxide semiconductor [CMOS] and silicon germanium) and leveraging maturing RF microelec- tromechanical systems (MEMS). In addition, higher levels of circuit board integration with fewer manufacturing steps and surface mount assembly connectors to eliminate expensive interconnects further reduce costs. Environmental protection technologies also eliminate the need for hermetic packages enabling more affordable and lightweight circuit card assembly (CCA) arrays as the major building block of a broad class of phased arrays. Radiating Elements Phased array radiator evolution has advanced through many improvements since the first explorations of array mutual coupling. Today’s radiators have the advantages of high efficiency, advanced polarization purity, wide bandwidth and scan volume, as well as reduced component and system cost. The evolution of the devices has been matched by an evolution in understanding, modeling and simulating complex electromagnetic phenomena and interactions; evolving from the first analytic expansion of the dipole electric field to the complex frequency-time domain three-dimensional full-wave solvers used today. Some of the first dipole phased array radiators were used by Raytheon in early warning radar systems such as the Precision Avionics Vectoring Equipment Phased Array Warning System (PAVE PAWS) in a dual polarization configuration. At the same time, important advances were made in waveguide radiators which began use in our missile defense family of radars. Printed circuit radiators, such as the patch and stacked patch, emerged in prominent systems including the Iridium global communications system. These radiators have all of the characteristics of waveguide cavity radiators, but with boundary conditions stemming from the array environment instead of the physical unit cell properties. The stacked patch radiators expanded the operating frequency bandwidth by as much as a factor of two compared to prior approaches. FEATURE RADIATING ELEMENTS Thumbtack Printed Circuit Flared Notch Dielectric Loaded D Waveguide W Tightly Coupled Dipole With MagnetoDielectric Loading Printed Circuit Stacked Patch Duall PPolarization FFolded ld d D l i Dipole ACTIVE DEVICES & MONOLITHIC MICROWAVE INTEGRATED CIRCUITS (MMICs) GaN, CMOS MMICs Discrete Devices Si Bipolar MASTER ER OSCILLATORS MESFETs, pHEMTs, mHEMT mHEMT, HBTs HBTs, SSiGe GaAs, MMICs, Si ASICs Quartz Oscillators Q (photo courtesy of Wenzel) ( BEAM FORMING AND SIGNAL DATA PROCESSING Analog Coaxial, Stripline, Microstrip Analog Combiners PACKAGING Brick Architecture Packaging & Electronics Orthogonal to Aperture Surface Acoustic (SAW) Wave Oscillators EVOLUTION FROM ANALOG TO DIGITAL Transmit/ Receive Modules (TRMs) 1980s Digital SubarrayLevel ArrayLevel ADC ElementLevel Circuit Card Assembly (CCA) Architecture Packaging & Electronics Parallel to Aperture Multichannel TRMs 1990s ADC ADC ADC ADC ADC Digital Summation Beam 1 Beam 2 Beam 3 Moduleless TRIMMs With Integrated Radiating Elements Transmit/Receive Integrated Multichannel Modules (TRIMMs) Tile Architecture Packaging & Electronics Parallel to Aperture 1970s Sapphire Oscillators E A R LY 2 0 0 0 s MMIC Chips on Circuit Card Assemblies With Embedded Interconnects TO D AY TOMORROW RAYTHEON SYSTEMS* PAVE PAWS & BMEWS EWRs F-15 & F-18 Airborne Radars SPY-3 CJR F-18G NGJ Pod JLENS SuR/FCR DDR ROTHR Iridium Main Mission Antennas AMDR GBR, AN/TPY-2, SBX Missile Defense Radars CEC DDS Radio *Partial ASTOR SYSTEMS LEGEND AMDR = Air and Missile Defense Radar AN/TPY-2 = Army Navy/Transportable Radar Surveillance – Model 2 ASTOR = Airborne STand-Off Radar BMEWS = Ballistic Missile Early Warning System CEC = Cooperative Engagement Capability CJR = Cobra Judy Replacement DDR = Dismount Detection Radar DDS = Data Distribution System TECHNOLOGY LEGEND EWR = Early Warning Radar ADC = Analog-to-Digital Converter GBR = Ground Based Radar ASIC = Application Specific Integrated Circuit JLENS SuR/FCR = Joint Land-attack Elevated Networked Sensor Surveillance Radar/Fire Control Radar NGJ = Next Generation Jammer PAVE PAWS = Precision Avionics Vectoring Equipment Phased Array Warning System COTS = Commercial off the shelf GaAs = Gallium Arsenide GaN = Gallium Nitride HBT = Heterojunction Bipolar Transistor HF = High Frequency MESFET = Metal-Semiconductor Field Effect Transistor mHEMT = Metamorphic High-Electron-Mobility Transistor = Relocatable Over The Horizon Radar MMIC SBX = Sea Based X-Band radar SAW = Surface Acoustic Wave SPY-3 = Navy Shipboard Radar designation Si = Silicon SiGe = Silicon Germanium ROTHR = Monolithic Microwave Integrated Circuit pHEMT = Pseudomorphic High-Electron-Mobility Transistor Figure 1. Active electronically scanned array (AESA) technology evolution RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 9 FEATURE Wideband radiators, such as the Vivaldi flared notch emerged to address the needs of wide bandwidth systems. The flared notch provides broadband performance with nominally linear polarization. Because of its broad beamwidth, it is ideal for electronically scanning antenna arrays with scan volumes of at least 60 degrees. For the past decade, Raytheon has pioneered taper optimization approaches which compress the notch length significantly below that of common exponentially tapered notches while also extending bandwidths up to 10:1. With a pair of orthogonally polarized elements, virtually any arbitrary polarization can be achieved at any given beam scan position when amplitude and phase control is employed. Raytheon AESA Research: Past, Present and Future balun embedded in the circuit board below the ground plane or printed on the substrate of the radiator structure. The design can be scaled to various bands ranging from HF to Ku frequencies. The thumbtack radiator has a coincident and stationary phase center over bandwidths up to 10:1. In addition, the thin and planar structure produces a very low cross polarization component, a desired feature for many advanced systems. Tightly coupled dipole arrays (TCDAs) are also being developed for AESA-based systems requiring ultra-wideband operation and lowprofile packaging (Figure 2). The TCDA design takes advantage of novel magneto-dielectric Raytheon’s long-term commitment to the development of GaN technology began nearly 15 years ago, and has leveraged its long history of GaAs semiconductor work, as well as partnerships with industry, academia and government. Printed circuit radiating elements opened the door to further cost reduction through low cost manufacturing techniques. The thumbtack radiator is a low profile antenna which matches to free space directly without a long flared notch to perform an impedance transformation. Each thumbtack radiator is fed by a Figure 2. Tightly coupled dipole array (TDCA) enables wideband and low profile solutions. 10 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY loading materials with advanced dielectric wide angle impedance matching (WAIM) structures to push efficient operational bandwidths into the range of 20:1. This may be achieved with antenna depths of 1/40th of a wavelength at the lowest frequency of operation, an orderof-magnitude thinner than traveling wave radiators of the same bandwidth. The dipole nature of the radiator naturally lends itself to dual polarization collocated phase center architectures, thus allowing synthesis of arbitrary polarizations. Due to its reduced height and planar construction, it exhibits improved polarization purity, especially during diagonal plane scanning, compared to deeper or tapered radiators. Active Devices and MMICs In the 1970s as an alternative to vacuum tubes, discrete transistors, mainly composed of silicon, were used in a hybrid configuration in arrays. Large, lumped element capacitors and inductors were used to match these transistors at microwave frequencies to standard impedances. Industry attention and movement from hybrid microwave integrated circuits to monolithicbased approaches began due to the requirements for low cost, mass production compatible circuits providing increased integration, reliability and multi-octave performance. Development of MMIC devices began in the early 1980s when gallium arsenide (GaAs) was emerging as the semiconductor of choice for efficiently amplifying and phase shifting RF signals. Efforts ramped up in the 1990s, as GaAs-based MMICs were introduced into large production programs for a new generation of phased array radars. Over time, the performance requirements of military systems became more challenging thus requiring further improvements to MMIC power, efficiency and low noise performance. GaN MMIC technology was pursued to help meet these new higher performance military system requirements. Raytheon’s long-term commitment to the development of GaN technology began nearly 15 years ago, and has leveraged its long history of GaAs semiconductor work, as well as partnerships with industry, academia and government. Raytheon’s development history with GaAs provided the needed infrastructure and lessons-learned experience to accelerate GaN’s development. This included the growth of starting material, the modeling of a GaN transistor’s RF performance, the semiconductor fabrication facility, the microwave and module design and the testing capabilities. Through early strategic partnering with Cree, the University of California Santa Barbara and U.S. government labs during the Defense Advanced Research Projects Agency (DARPA) Wide BandGap Semiconductors (WBGS) Phase II program, the team was able to shorten the cycles of learning and leverage each other’s findings to more quickly advance the state of GaN transistors (Figure 3). Raytheon’s focus on early reliability demonstrations and transition to 4-inch wafers, to leverage the existing GaAs manufacturing facility, resulted in an industry leading manufacturing readiness level (MRL) of 8 accomplished under Raytheon’s Office of Secretary of Defense Title III program. FEATURE gies (GaN HEMTs and Si CMOS) could coexist on the same Si substrate. The performance impact to both the Si CMOS and GaN HEMT circuits was minimal. This technology provides an opportunity to enable digital control and optimization of RF and mixed signal circuits (e.g., amplifiers with on-chip digital control and calibration), adaptable or linearized bias controlled power amplifiers (PAs), high-power digital-to-analog converters (DACs) and many other novel on-chip capabilities with better RF performance than silicon germanium (SiGe) devices. Figure 3. Early GaN wafer developed and tested as part of the Raytheon and DARPA GaN MMIC maturation programs. In addition to GaAs and GaN MMIC development, our research and investments extend to customizing the many unique and prolific MMIC functions that make up our modules. Our GaAs pseudomorphic high electron mobility transistor (pHEMT) technology development focused on the MMICs which provide the amplitude and phase control and enabled an efficient digital interface. The pHEMT process mixes RF and logic functions on the same GaAs MMIC. This optimizes efficient serial or parallel logic interfaces to a silicon (Si) controller chip which extends to the beam steering electronics. This unique capability in a GaAs MMIC enables logic functions locally and minimizes the number of off-chip components and interfaces, improving reliability, producibility and reducing the AESA’s size and cost. Master Oscillators AESA based radar systems require very low noise sources for their master oscillators to take advantage of the high dynamic range enabled by the AESA. High-performance, low-phasenoise sources have evolved over the decades from frequency-multiplied quartz crystal oscillators in the earliest AESA-based systems to frequency-multiplied surface acoustic wave (SAW) oscillators in the 1980s. This technology evolution enabled higher levels of sensitivity and dynamic range with Raytheon’s novel SAW resonator and oscillator technologies delivering outstanding radar system performance for several decades. The emergence in the mid-1990s of new threats and the need to operate in high clutter environments called for even more demanding radar sensitivity requirements that pushed the limits of SAW-based exciters. By the early 1990s, Poseidon Scientific Instruments (PSI) developed a compact sapphire resonator. It employed a single synthetic sapphire resonator that offered orders of magnitude reduction in microwave oscillator noise over our SAW-based solutions. By 2000, PSI had fully productized their compact sapphire-based oscillator into a shoebox size form factor suitable for radar applications. This sapphire oscillator technology now enables even higher performance and continues to provide Raytheon radar systems with industry leading levels of performance. Beamforming and Signal/Data Processing Beamforming in early AESAs at the low frequencies (e.g., UHF) was primarily just coaxial cabling and commercial off-the-shelf (COTS) connectorized combiners. At higher frequencies, waveguide manifolds, printed circuit (Figure 4) or microstrip combiners were typically employed for analog beamforming due to their cost, weight and size advantages. Today, we still use variations of the same core technologies, however the manufacturing capabilities and material choices are more diverse. Future passive analog RF beamforming components will continue to leverage new materials as they become available, further improving integration, interconnects and reducing cost. The emergence of digital beamforming and signal processing began in earnest in the 1990s when analog-to-digital converter (ADC) technology began to be commercialized in the RF domain for the wireless industry. Major The extension of the pHEMT process to other heterogeneous MMIC integrations has continued under independent research and development (IRAD) and DARPA investments. Our research interests now include technologies that directly integrate GaAs, indium phosphide (InP) and GaN RF devices with high density Si CMOS logic on a single Si wafer. This heterogeneous integration process and technology provides a path for optimization of specific functionality and digital control using the best active device technology and minimizes further the number of interconnects. We demonstrated the world’s first heterogeneously integrated MMIC using GaN high electron mobility transistor (HEMT) and Si CMOS devices. A GaN RF amplifier using a Si CMOS gate bias control proved that the two technolo- Figure 4. The Rotman-Turner lens is an example of a stripline beamformer design that can offer low-cost, wideband performance in a compact size. RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 11 FEATURE improvements in resolution due to lower jitter and power dissipation opened up new applications. Many military AESA radar systems benefited from these improvements as well. Much of the commercial industry research focused on Si, however other higherend military systems developed converters based on InP electronics for higher sampling rates and dynamic range. Most of today’s AESA radar systems have only a handful of digitized receiver channels, thus the entire dynamic range burden is placed on only one or a few converters. The next generation of AESA systems will have digitization at the subarray level, and some will extend to the element level. Thus hundreds to thousands of digital channels and degrees of freedom will be available for advanced signal and data processing. This will enable unprecedented performance and new capabilities for radar, communications and EW missions such as creating and processing multiple simultaneous beams, increased polarization diversity and improved dynamic range. Digitization at the AESA element level will also simplify transmit/ receive module (TRM) functionality by no longer requiring the MMICs for amplitude and phase control. Digitization of AESAs is not limited to just advances in ADC technology. Advances in the ability to move and process received data in the digital domain also continues to rapidly advance. Signal and data processors have benefited from Moore’s law1 to become much more capable, lower power, smaller and more affordable, enabling the implementation of new and more sophisticated processing of the received data. Packaging During the 1980s, many airborne AESAs were constructed using hermetically sealed housings, typically aluminum, with glass to metal sealed RF and direct current (DC) connectors. However, AESA TRMs used for UHF surface-based radar applications used sealed, but not hermetic, assemblies due to their large size. Many of the components were mounted to ceramic carriers with fluxless solders such as gold-tin. These carriers contained discrete, bipolar transistors, field-effect transistors (FETs) or simple microwave integrated circuits (MICs). Due to the coefficient of thermal 12 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Raytheon AESA Research: Past, Present and Future expansion (CTE) mismatch between the carrier and housings, the carriers had to be mounted to the housings with screws. These modules were large, complex and costly, but were successfully used in the first X-band solid-state phased array (SSPA) that employed fundamental frequency amplification for transmit. The multiple thermal interfaces between the heatgenerating regions of the active devices and the cooling system had a major impact on the packaging, reliability and replacement strategy of the modules. The X-band airborne module was approximately 1.5 x 5.2 x 0.5 inches while the UHF module was at least twice the size. Major thrusts during the 1990s were launched to reduce cost and increase performance of modules and arrays. Advances in MMIC technology yielded chips with greater power and more on-chip capabilities, resulting in a reduced numbers of chips per module. The new, more capable MMICs and the development of low CTE housings with ceramic feedthroughs, ionically pure die attach adhesives and fine feature thick films helped usher in the next generation of modules. These modules, developed for airborne and surface radars, are fabricated using automated assembly methods and are much smaller than their module predecessors. These MMIC modules were assembled into a brick-style transmit/receive integrated multichannel module (TRIMM). The MMIC modules, RF and DC circuit cards and radiating element were attached by a combination of adhesive bonding and fasteners to an aluminum cold plate. Interconnection between the MMICs, RF and DC circuit cards and the radiating elements was accomplished with ribbon connectors in place of rigid connectors. The elimination of the rigid connectors greatly reduced the cost and weight of the assembly. The next evolution of hermetic module packaging was the development of multichannel modules, for example the High Density Tile Module – 4 channel, mark number design variant 1 (HTM4 Mk1). The HTM4 Mk1 module consists of a multilayer high temperature thin-film ceramic (HTTC) substrate that contains the RF circuitry, a multilayer thick film substrate with DC and logic circuitry, and an interposer which connected the two substrates into a single package. The HTM4 Mk1 design allowed four complete transmit/receive (T/R) functions to fit into a 1 x 1 inch package. Further evolution of the multichannel module package resulted in a single multilayer HTTC substrate and a copper-molybdenum thermal plane with a kovar ring frame and lid, thereby reducing both cost and weight. HTM4 modules evolved into what is known today as the tile module. The tile module has RF and DC inputs and outputs on different planes (opposite sides) that are assembled into the array in a tiled x-y matrix. Interconnections between the module, radiating aperture and control circuitry are made by spring pin interconnects rather than more traditional RF connectors or wire bonds, allowing for simplification of the array assembly. The AESA’s next packaging evolution was the development of arrays that did not rely on hermetic modules to package the T/R functionality. Module-less TRIMMs were developed where the RF and DC routing was accom- Major thrusts during the 1990s were launched to reduce cost and increase performance of modules and arrays. Advances in MMIC technology yielded chips with greater power and more on-chip capabilities, resulting in a reduced numbers of chips per module. 1 Moore’s law is the observation that the number of transistors in an integrated circuit doubles approximately every two years. Increased computer processing and memory capabilities are strongly linked to the density of transistors in an integrated circuit. FEATURE TRIMM Features • Liquid (higher power density) or air cooled • Packaged face up or flipped MMICs • Small number of circuit layers • Primarily touch labor assembly • Drives the AESA depth CCA Features • Liquid (medium power density) or air cooled • Packaged face up or flipped MMICs • Large number of circuit layers • Automated fabrication, pick and place • Enables a thinner AESA Figure 5. Evolution from transmit/receive integrated multichannel module (TRIMM) to circuit card assembly (CCA) packaging provides size, weight and cost reductions. plished using advanced printed wiring boards (PWBs). PWB technology had advanced to a point where high performance RF laminates could be combined with traditional DC laminates to produce multichannel substrates suitable for AESA applications. These TRIMMbased module-less arrays were first developed with channel counts ranging from four to 60. These TRIMMs consisted of a multilayer RF/DC PWB populated with a mixture of traditional surface mount technology (SMT) devices and chip and wire RF devices. These substrates could include either radiating elements or simple nonhermetic RF connectors. Environmental protection for initial applications was provided via a sealed enclosure. For future systems, Raytheon is developing coating technologies to eliminate the need for a sealed enclosure. Circuit card assembly (CCA) arrays that incorporate advanced printed circuit radiating elements were developed to provide reduced antenna depth over the module-less TRIMMs (Figure 5). The CCA approach uses stacked layers to produce arrays which are exceptionally thin and lightweight. Advanced RF/DC PWB substrates are used to produce subarrays with channel counts more than 1,000. Typically, small daughter cards with either flip-chip or upright components that contain the RF components are used in CCA construction. The daughter cards are attached either mechanically or through SMT soldering to a larger mother board containing the DC distribution network, capacitors and other components. The aperture, RF, DC, control layers and cold plates are all mechanically fastened together to form a single CCA subarray. Subarrays can then be joined to create a full array of the needed size. The development of GaN-based MMICs has required new packaging to handle the higher operating voltages and increased thermal loads. The higher power levels obtainable with GaN-based TRMs allow arrays to be greatly reduced in overall size and element count, however, this reduction has resulted in unprecedented power levels and thermal loads to be dissipated at each module. As such, hermetic housings constructed of new materials with higher thermal conductivities are being developed, including mixed-metal composites, nano-material based thermal interface materials and ultra-high performance cold plates. Power and Cooling As with packaging, AESA thermal management and power conditioning has changed dramatically during the last 30-plus years. The RF devices in an AESA can generate large heat flux levels, and the thermal management of AESA systems has spurred development of higher performance liquid flow-through cold plate technology, thermal interface materials, and controlled CTE packaging materials. Arrays in the 1980s used heat pipes to reduce the temperature rise between the electronics and the ambient environments. As packaging approaches evolved to higher densities, thermal management solutions evolved to using smaller air or liquid heat sink assemblies. Liquid cooling is typically the choice for thermal management of high performance AESA-based electronics, and is the most efficient and affordable approach to maintaining the required MMIC and TRM temperatures needed to achieve high reliability and electrical performance. Some liquid-cooling solutions provide the cooling channels directly under the TRMs or MMICs and others conduct the heat away from the TRMs or MMICs to a liquid cooled manifold. For further cooling efficiency, new liquid-cooling designs position the fluid even closer to the MMICs using integrated nano- and micro-size channels in planar volumetric cooling architectures and novel heat spreader designs. Air-cooled approaches are also used for some applications, especially for small low-power devices. Air-cooled approaches are often simpler and lower cost versus liquid-cooled designs and can be used when the system requirements allow it. Power conditioning technology has also improved over the years with the development of planar magnetics and smaller devices. Many of the smaller AESAs use centralized power conditioning due to the proximity opportunities of the supply and AESA. The larger AESAs must distribute the power conversion electronics in order to minimize the size and weight of the conductors and to improve efficiency. The use of higher voltage GaN allows smaller conductors to be used and improves the overall power efficiency allowing significantly lighter power conditioning systems. Summary Raytheon, including legacy Hughes, Texas Instruments Defense and E-Systems companies, provides unparalleled AESA research, development, manufacturing and product experience for surface, airborne and space missions in radar, communications and EW systems. Working with our government investment partnerships for more than 30 years, Raytheon has pioneered and matured AESAs and their dependent technologies into fielded solutions for our nation’s warfighters and allies. Raytheon continues to be an industry leader in developing advanced technologies such as high-power GaN MMICs, integrated RF electronics packaging and interconnects, more efficient power and thermal conditioning solutions and new subarray and element level digital beamforming and signal/data processing techniques to continue providing affordable solutions for a diverse customer base. • Mike Sarcione, Porter Hull, Colin Whelan, Doug Tonomura, Thomas V. Sikina, Jim Wilson and Robert E. Desrochers II RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 13 FEATURE State-of-the-art RF Semiconductors FOR MILITARY SYSTEMS M odern military systems require the highest performance radio frequency (RF) semiconductor technology. For example, in radars in transmit mode, RF energy needs to be distributed to each active antenna array element, precisely phase shifted and then greatly amplified before being radiated, and in receive mode, the small return signal must be amplified with great fidelity. Likewise, electronic warfare (EW) and communication systems require the same sort of transmit and receive functionality with even more emphasis on signal fidelity in both transmit and receive modes. The final active array amplification of transmitted RF signal at each element is performed by a compact RF power amplifier (PA) circuit chip that is a type of monolithic microwave integrated circuit (MMIC). This PA technology must be small enough to fit within the radar’s element spacing, be able to generate high RF output power and also be very efficient in converting direct current (DC) power into RF power to minimize prime power consumption and waste heat generation. In receive mode, the first stage of amplification of the reflected signal is performed by a low noise amplifier (LNA) MMIC which must increase the desired signal strength while minimizing additional noise degradation and the introduction of nonlinear distortions. The phase shifter MMIC within each radar element allows dynamic beam steering of the radiated RF energy. Raytheon, leveraging its own trusted foundry (Figure 1), has a long and successful legacy of developing next generation, high performance semiconductor processes for PA, LNA and phase shifter MMICs as well as for inserting them into highly reliable, fielded, phased array radars. This MMIC design and fabrication capability coupled with expertise in semiconductor material growth, MMIC-based module development, and integration and test, provide a leading edge RF MMIC capability that supports current and emerging Department of Defense (DoD) system needs at a lower cost and shorter timeline than alternative approaches. Specifically, today’s commercial RF capabilities, that are driven primarily by commercial technology demands, cannot meet the most stressing DoD system requirements. Semiconductors for Combined RF and Logic Functionality Traditionally, gallium arsenide (GaAs) has been the semiconductor of choice for efficiently amplifying and phase shifting RF signal in radars. Throughout the 1990s, Raytheon was a pioneer in inserting GaAsbased MMICs into the first modern phased array radars. As the performance requirements of these military systems have increased to meet ever-growing threats, so too have the Figure 1. Raytheon’s trusted semiconductor foundry facility fabricates gallium arsenide and gallium nitride monolithic microwave integrated circuits. 14 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY FEATURE Raytheon Process Description Radar Functionality GaAs pHEMT Traditional PAs and LNAs GaAs pHEMT with logic Multifunction MMICs Heterogeneous integration RF with complex logic or control mHEMT Higher performance LNAs GaN Higher performance PAs During the past six years under independent research and development (IRAD) and Defense Advanced Research Projects Agency (DARPA) funding, Raytheon has taken the integration of RF and logic functions to the next level. Raytheon has developed technology to directly integrate GaAs, indium phosphide (InP) or gallium nitride (GaN) RF devices with high density Si complementary metal oxide semiconductor (CMOS) logic on a common Si substrate. This heterogeneous integration technology enables greater levels of functionality and digital control of RF circuits as well as a reduction in cost over using the traditional separate RF and logic chips. Table 1. Raytheon’s customized semiconductor processes optimized for each radar function. power, efficiency and low noise requirements on these MMICs. During that time, Raytheon has continued to customize and optimize its semiconductor processes for each specific radar function (Table 1). One such Raytheon GaAs pseudomorphic high electron mobility transistor (pHEMT) technology, customized for multifunction MMICs containing phase shifters, attenuators and gain stages, combines RF and logic functions on the same MMIC, providing a serial or parallel logic interface to a separate silicon (Si) controller chip. By designing a process that allowed the combining of some logic functions on the RF MMIC circuitry, the number of off-chip components and interfaces between chips was minimized, reducing size and cost while improving radar manufacturability. Using this integration approach, Raytheon demonstrated the world’s first GaN HEMT and Si CMOS heterogeneously integrated chip; a GaN RF amplifier with in-situ Si CMOS gate bias control (Figure 2). This circuit was a proof of concept that demonstrated that GaN HEMT and Si CMOS devices could be integrated on the same Si substrate with minimal performance impact to the Si CMOS and GaN HEMT technologies. The circuit also serves as a building block for digitally assisted RF and mixed signal circuits, such as amplifiers with on-chip digital control and calibration, reconfigurable or linearized PAs with in-situ adaptive bias control, high-power digital-toanalog converters (DACs) and on-chip power distribution networks. GaN HEMT Si CMOS Figure 2. Optical micrograph of the first GaN and Si CMOS heterogeneously integrated MMIC. Semiconductors for Low Noise Amplification For low noise amplifications such as what is used in radar receivers, Raytheon developed high indium-content metamorphic HEMT (mHEMT) technology and manufacturing processes for higher gain performance with even lower noise contribution than traditional GaAs HEMT technology that is limited to 19 percent indium in the channel region where the electrons travel. Previously, only InP HEMT devices with high indium content (53 percent) in their InGaAs quantum well channels could fill this ultimate low noise function, but at a higher cost due to the challenges associated 25 GHz Fmin (2 x 50 μm) 1.0 ) cale ft S e Le (Us 8,000 0.8 6,000 GaAs 4,000 Devices ale) t Sc igh se R (U 0.6 InP Devices 0.4 2,000 0.2 Fmin 19% In pHEMT Fmin 33% In mHEMT 1.25 Fmin (dB) 10,000 Quantum Well Depth (eV) Mobility of Electons (cm2/V-s) 1.5 1.2 12,000 Fmin 60% In mHEMT 1 0.75 0.5 0.25 mHEMTs 0.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Indium Channel Content (In(x)Ga(1-x)/As) Figure 3a. With metamorphic high electron mobility transistor (mHEMT) technology, as indium (In) is added to the quantum well channel, both electron mobility and quantum well depth increase. 0 0 50 100 150 200 250 Current (mA/mm) Figure 3b. As indium (In) is added to the quantum well channel, the minimum noise figure (Fmin) decreases. RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 15 FEATURE State-of-the-art RF Semiconductors for Military Systems with manufacturing MMICs on fragile InP wafers. mHEMT technology, with up to 60 percent indium composition in the channel, offers the gain and low noise performance advantage of InP HEMTs and the manufacturability and cost advantages of GaAs MMIC wafers. Through the growth of a metamorphic material layer on a GaAs substrate, the lattice constant of GaAs can be transformed to allow the growth of higher indium content InP HEMT devices on GaAs wafer substrates. Additionally, metamorphic growth allows classically forbidden indium contents to be grown, i.e., those not lattice matched to GaAs or InP substrates, thus enabling the device designer to explore and exploit the properties of a new set of HEMT devices. Figure 3a shows that the measured mobility of channel electrons increases with increasing channel indium content, due mainly to the reduction in electron effective mass and reduced scattering in the deeper quantum well. These improvements give rise to higher electron channel velocities, allowing operation at higher gain, higher frequency and lower noise figure than GaAs devices. Figure 3b shows the reduction in minimum noise figure, Fmin1, achieved as one moves from a traditional GaAs pHEMT device with 19 percent indium content to that of a mHEMT with a 60 percent indium content InGaAs channel. When fabricated into LNAs, these mHEMT MMICs greatly improve the signal-to-noise ability of the system, extending its range while reducing prime power over GaAs technology as the high mobility enables them to operate at lower DC bias. Semiconductors for High-Power Transmission For improvement on the transmit side, Raytheon developed and matured GaN technology for PAs, enabling the next generation of DoD systems. The power, efficiency and bandwidth performance of GaN-based MMICs is unsurpassed, revolutionizing the design of radars by creating not only higher performance but also lower system cost. With over 5 Watts/millimeter (W/mm) of RF output power density compared with GaAs at 1 W/ mm, GaN RF amplifiers deliver five times the power per element compared to GaAs within the same footprint, providing up to 50 percent more radar range or the ability for the radar to search five times the volume of space in the same amount of time (Figure 4). Fewer highpower GaN MMICs could be used to replace many low-power GaAs MMICs, decreasing radar size by half while maintaining search TRACK SEARCH Search volume with GaAs Range using GaAs Radar Array Face 1.5x Range using GaN Reference target size 5x volume with GaN Identical target Radar Array Face Range Window 1) Five times the search volume in the same amount of time. 2) 50 percent increase in range with the same sensitivity. OR APERTURE SIZE Search volume with GaAs Reference area with GaAs 50 percent area with GaN Radar Array Face Greater volume with GaN 3) 50 percent reduction in antenna size with greater search volume. Assumes GaN power = 5x GaAs power Figure 4. GaN technology provides significantly improved radar performance compared to GaAs at reduced size and cost. 1 Fmin is a measure of signal to noise during RF signal amplification. 16 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY FEATURE Log – Normal Failure Distribution Failure Distribution (Arbitrary units) 0.6 0.5 0.4 0.3 0.2 30 year mission requirement 0.1 0.0 1.E+3 1.E+4 1.E+5 1.E+6 1.E+7 1.E+8 1.E+9 1.E+10 1.E+11 1.E+12 Time (Hr) Figure 5. Calculated failure distribution at 150 °C based on measured accelerated GaN device testing. Lifetimes, denoted by the failure distribution, greatly exceed the 30-year DoD system mission life. performance and increasing efficiency or, alternatively, equal-power GaN chips can be made dramatically smaller in size. Thus, GaN can reduce overall system costs while enabling new smaller size-constrained systems. The higher drain current that GaN offers makes the broadband matching of high-power EW MMICs simpler and more efficient than GaAs, while the approximately seven-fold improvement in the thermal conductivity enables efficient amplifier cooling. Finally, the wide bandgap that is intrinsic to GaN material provides large critical breakdown fields and voltages, making a more robust amplifier and easing system implementation. Recently, Raytheon was honored by the Office of the Secretary of Defense (OSD) for their successful completion of the Defense Production Act (DPA) Title III GaN production improvement program, culminating over a decade of government and Raytheon investment in GaN technology. Raytheon also demonstrated that the reliability of our GaN technology exceeded the 30 year mission requirement for insertion into production military systems (Figure 5). This maturation of GaN resulted in a manufacturing readiness level (MRL2) of 8, the highest level obtained by any organization in the defense industry for this technology. Also, through the Title III program, Raytheon demonstrated that GaN MMICs could generate RF power for one third the cost of GaAs MMICs, enabling higher performance systems at a lower cost. Future Semiconductor Technology Raytheon continues to pioneer the development and manufacturing of cost-effective, next generation RF semiconductor technologies to deliver needed capabilities for current and future defense electronic systems. One such technology for power amplifiers is polycrystalline diamond which provides very high thermal conductivity, allowing GaN to reach its full potential in RF power density and compactness while maintaining reliable operating temperatures. For next generation receivers, InGaAs with indium contents exceeding 60 percent are being explored to further improve noise figure and lower DC power consumption. All of Raytheon’s semiconductor research technologies strive to achieve higher system performance for the warfighter at lower costs than existing capabilities. • E N G I N E E R I N G P R O F I L E FEATURE Steven Bernstein Principal Engineering Fellow, Advanced Technology Programs Steven Bernstein is a program and capture manager at the Raytheon Integrated Defense System Advanced Technology Programs organization with more than 25 years of experience in semiconductors, electronic devices, transmit/receive modules, transmit/receive integrated multichannel modules (TRIMMs) and radar systems. He is currently responsible for radar component technology development including both RF component and power system technologies. “Through the years, my focus has changed,” Bernstein acknowledges, “from optical and electronics materials development to radar component technologies … My interest in developing technology, however, has always remained the same.” Bernstein is the Raytheon program manager for several Defense Advanced Research Projects Agency (DARPA) and Office of Naval Research (ONR) programs as well as several Raytheon independent research and development activities. These include the DARPA Near Junction Thermal Transport (NJTT) program which is involved in the development of gallium nitride (GaN)-on-diamond technology, the DARPA Wide BandGap Semiconductor (WBGS) Phase 3 program which is developing GaN-based T/R modules and the ONR Compact Power Conversion Technology program which is developing the next generation of power system technology. Previously, he was the Raytheon program manager for the DARPA Wide BandGap High Power Electronics program and several thermal management programs. He received the Raytheon Excellence in Technology award for his work on GaN technology. Earlier in his career, Bernstein was on the staff of Raytheon’s Research Division. His work at the Research Division focused on gallium arsenide (GaAs) process engineering, the development and demonstration of novel electronic ceramic thin-film devices based on high temperature superconductors and ferroelectric materials, and the development of novel infrared window solutions for high speed missiles. When asked about some of the more exciting aspects of his job, Bernstein said, “I work many different programs and technologies so every day is different. I am also excited when we take a risk on something new and accomplish something that has never been done before.” Colin Whelan, Nicholas Kolias, Joseph Smolko, Thomas Kazior and Steven Bernstein 2 MRL is a measure used by the DoD and many of the world’s major companies to assess the maturity of manufacturing readiness. RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 17 FEATURE COMPUTATIONAL IMAGING TECHNOLOGY Revolutionizing Digital Imaging New capabilities allow for the practical application of exciting computational imaging technologies that will revolutionize digital imaging systems to meet the expanding sensing needs of our customers. I maging technologies of the 21st century are advancing at a fast pace. Key technical advances are being made daily in the performance and capabilities of imaging detectors, high-definition displays, high-bandwidth networks and distributed high-performance computing. These new capabilities allow for the practical application of exciting new imaging technologies that are the synergistic fusion of optics and detectors, and allow the use of computing capabilities and algorithms that will revolutionize the field of digital imaging. This emerging technology area, known as computational imaging, has the potential to provide our customers with the actionable information they actually need, instead of drowning them in data and hoping they can find the desired information amongst all the raw imagery. As a leader in developing and manufacturing advanced electro-optical (EO) imaging systems for a wide variety of intelligence, surveillance and reconnaissance (ISR), security and effects targeting needs, Raytheon is exploring the powerful potential emerging from the application of computational imaging technologies. Addressing Current Sensing Systems Needs For the past four centuries, imaging systems were designed as two separate entities: the image forming components (i.e., optics), and the image detection components (i.e., eye or film). The transition to electronic focal plane array detectors as a replacement for the human eye or silver halide film has done little to change this design architecture. However, during the past decade, the rapid increase in practically available computational power has led many to explore whether there might be an advantage to the joint design of these optical detection systems. 18 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Computational imaging is an emerging new technology area, one with the potential to dramatically impact EO sensing system capabilities over the coming decade. Computational imaging refers to the synergistic combination of traditional and nontraditional optics, detectors and computational resources in order to achieve gains in system performance (e.g., increased detection ranges; decreased system size, weight and cost; additional and improved extraction of desired information from scenes beyond just imagery). These system attributes are the key technical performance measures customers are looking for in determining solutions for their sensing system needs. The essence of computational imaging is the concept that there are significant gains to be had from inserting the computational step earlier into the image acquisition and formation chain — not just by performing processing post-image formation — to produce improved and specialized forms of scene information. This scene information can be purpose rendered to meet the operational information needs of the end user. The application of computational imaging technologies to current-day ISR, security and targeting systems can potentially provide improved performance for many technical attributes: • Reduced physical size and weight of imaging systems. • Reduced demands on high-bandwidth communications/networks. • Improved performance attributes relating to multispectral and hyperspectral data, threedimensional imagery, image spatial resolution and dynamic range. • Improved image exploitation attributes relating to automated target cueing, scene change detection, detection and tracking of objects of interest and improved situational awareness over large areas under surveillance. Exploring New Sensing Capabilities Raytheon businesses span a diverse base of EO sensing products, covering a broad range of military, civil and international markets. Computational imaging technology similarly spans a wide spectrum of potential capabilities and applications. Key application areas where the use of computational imaging design concepts and principles could potentially be employed include: • Ultra-wide field-of-view (FOV) imaging for ISR and security applications. • Spatial resolution enhancement for ISR, targeting and security applications. • Novel multispectral and hyperspectral imaging for ISR and security applications. • Reducing the size, weight and cost of optics and imagers for hand-held applications. • Digital processing to focus the operators’ attention on image content of interest to reduce data overload, increase the speed of understanding and improve efficiency and effectiveness. As much of the innovative research and development activity in this technology area occurs within the academic environment, Raytheon is collaborating with leading research universities to cooperatively explore computational imaging. In particular, Raytheon has been collaborating with Duke University, Rice University and the University of Arizona. Additionally, Raytheon has been collaborating with several small technology businesses identified through the Small Business Innovation Research (SBIR) program. These collaborative research efforts have focused on exploring these new technologies and their potential applications. FEATURE During these joint investigations, a wide range of potential applications were discovered. In particular, three areas were concentrated on for technical investigation: • Computational resolution enhancement. • Computational hyperspectral sensing. • Compact imaging optics. Computational Resolution Enhancement In a current trend mirroring that of consumer cameras, the pixel count in EO imaging systems continues to increase. The driving requirement for this is the need for greater scene spatial resolution. One example of the use of computational imaging technologies for this paradigm is being explored by a team led by Duke University as part of the Defense Advanced Research Projects Agency (DARPA) Advanced Wide FOV Architectures for Image Reconstruction and Exploitation (AWARE) program. The Duke University team has constructed wide FOV multiscale visible imaging cameras capable of producing diffractionlimited images as large as 10 gigapixels. An example of the high-resolution images generated by a Duke University 2-gigapixels prototype visible camera is shown in Figure 1. This is an exciting new imaging capability that has many applications in the surveillance, security and entertainment domains. Not all EO sensing applications, however, can afford or require the size, weight, power and bandwidth resources required by a gigapixelclass imaging camera. For these applications, Raytheon has been investigating techniques for collecting high resolution imagery with fewer actual pixels in the focal plane; a research area termed “compressive sensing.” Two different approaches are under development: • The single pixel camera imaging design concepts explored by Rice University. Through the use of a fast dynamic scene modulator, these imaging cameras use a low number of physical imaging detectors (less than 50) to capture compressed imagery containing up to a megapixel. • The coded aperture camera imaging design concepts pioneered by Duke University and the University of Arizona. Through the use of a high resolution coded aperture located in an intermediate image plane, imagery can be generated with an effective resolution of three times greater than the physical focal plane array in each dimension. Figure 1. Prototype gigapixel camera is capable of providing very wide field-of-view images while also providing very high image resolution and scene detail (photos courtesy of Duke University). Computational imaging techniques applied to hyperspectral sensing systems potentially provide data similar to the traditional designs at a much lower size, weight, power and cost. Computational Hyperspectral Sensing Raytheon has a significant technology presence with conventional hyperspectral sensing systems, ranging from the spaceborne Visible Infrared Imager Radiometer Suite (VIIRS) meteorological sensor and the Advanced Responsive Tactically Effective Military Imaging Spectrometer (ARTEMIS) to the Airborne Cueing and Exploitation System Hyperspectral (ACES Hy) tactical surveillance sensor. All of these units are traditional spectrometer designs. In collaboration with Duke University, Raytheon is evaluating the design concepts for a coded aperture hyperspectral sensor. This sensor concept, known as a coded aperture snapshot spectral imager (CASSI), is a snapshot multispectral or hyperspectral imaging sensor that utilizes a coded optical aperture with a dispersing prism or grating. The resulting dispersed spectra are overlaid on a staring focal plane array, and recovery of the image is performed by using an itera- RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 19 FEATURE Computational Imaging Technology is Revolutionizing Digital Imaging tive data recovery algorithm. Figure 2 shows a prototype CASSI camera operating in the shortwave infrared (SWIR) spectral region (1–1.7 m). Simulated hyperspectral imagery is also shown in this figure along with the anticipated processed results compared to measured spectral feature data. 0.025 LAKE 0.02 0.015 0.01 0.005 0 -0.005 0.1 Compact Tactical Imaging Optics Raytheon is known as a major provider of tactical hand-held thermal imaging systems to support warfighter effectiveness and increase their survivability in combat operations and environments. Examples of current and developmental tactical situational awareness and targeting systems include the family of Thermal Weapon Sights (TWS), PhantomIR and the Integrated Day-Night Sight Technology (IDNST) imager. 0 10 20 30 10 20 30 10 20 30 BUSH 0.08 0.06 0.04 0.02 0 0.012 0 ROAD 0.01 0.008 0.06 0.004 0.02 One of the major contributors to the size, weight and cost of these smaller military handheld imaging systems is the optics. Using computational imaging concepts, optical design alternatives for tactical situational awareness imagers were explored by Duke University, the University of Arizona and the University of California San Diego through their participation in the DARPA Multiple Optical Non-redundant Aperture Generalized Sensors (MONTAGE) program. As illustrated in Figure 3, these activities yielded several innovative lightweight optical designs suitable for tactical imagers. The Duke University team developed 0 0 Figure 2. Coded aperture snapshot spectral imager (CASSI) hyperspectral imaging camera is capable of providing multispectral and hyperspectral imagery in a compact package suitable for tactical ground and airborne platforms. an optical design that was only 5 millimeters thick and is significantly lighter than conventional optical design approaches. The University of Arizona and University of California San Diego team developed a compact folded optical design that has been evaluated by the U.S. Army Night Vision and Electronic Sensors Directorate (NVESD) for use on the TWS family of thermal night sights. These research and evaluation activities continue in an effort to provide enhanced tactical imaging solutions to warfighters. Future Directions Raytheon has been an active industry participant in the evaluation and development of computational imaging technologies over the past decade. Continuing these technical evaluation, development and prototyping activities will provide the objective insight to make informed technology deployment and investment decisions in the coming years. Working closely with university and technology-based small business partners, Raytheon continues to develop enhanced image generation and exploitation capabilities that meet current and future customer needs. • Randy Gann and Bob Gibbons DARPA MONTAGE Multi-aperture Lens DARPA MONTAGE Folded Imaging Optics Figure 3. Compact lightweight optical systems were developed under the DARPA Multiple Optical Non-redundant Aperture Generalized Sensors (MONTAGE) program to significantly reduce the size and weight of tactical imaging systems (Photos courtesy of Duke University [left] and the University of California San Diego [right]). 20 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY FEATURE BAREMETAL: a New Cybersecurity Technology The U.S. government and cleared defense contractors rely heavily on a commodity information technology (IT) infrastructure to plan and coordinate business practices and perform data processing. Unfortunately, commodity IT equipment is often manufactured in untrusted environments (e.g., foreign factories), shipped by untrusted companies and received by potentially malicious insiders, exposing new attack surfaces and putting the U.S. at risk for attack. While many organizations attempt to secure commodity desktop and server systems with personal security products and hardened operating systems, there is no verification that adversaries have not exploited their firmware through supply chain or remote attacks to facilitate cyberespionage or to disrupt operations. All commodity IT equipment uses firmware to initialize system components and to load the operating system. In desktops, laptops and servers, basic input/output system (BIOS) firmware has served this purpose. In recent years, however, unified extensible firmware interface (UEFI) firmware has started replacing legacy BIOS firmware. This new UEFI standard enables the development of highly modularized and well-formatted firmware, which allows developers to construct higher quality firmware more rapidly. The UEFI standard also lowers the barrier to entry for adversaries to inject low-level malware and exploit low-level vulnerabilities. Raytheon Pikewerks has developed a small, portable device called BareMetal that can be used by a nonspecialist to acquire, process and characterize computer firmware in a matter of minutes. BareMetal, shown with the cover removed in Figure 1, focuses on threats to UEFI and option read-only memory (ROM) firmware used to initialize peripherals like video and graphics cards. The device consists of an ARM-based1 computer-on-module (COM), a self-contained power source and light emitting diodes (LEDs) to inform users of analysis results and errors. BareMetal is intended for operators who know little about firmware or firmware threats. Operators need only configure a machine to boot off BareMetal and the device does the rest. Thus, BareMetal can be used to inspect firmware during provisioning and before the equipment is deployed within the IT infrastructure. Figure 1. The BareMetal device (shown with cover removed) contains processor, storage, user interface and power supply elements packaged into a small (3.0 x 2.1 x 1.2 inch) form factor enclosure. BareMetal can also be deployed in the form of an agent to provide situational awareness of unauthorized firmware modifications across an enterprise. A server-side component communicates with the agent to acquire firmware and process it to determine if any unauthorized changes have been made. Additionally, BareMetal is designed to cooperate with the Intel® Active Management Technology (AMT) so it can receive messages when a computer’s chassis is opened, when a computer unexpectedly reboots, or when a new peripheral device is inserted into the motherboard. All these events are considered possible indicators of a firmware or hardware attack. BareMetal, in its enterprise form, is designed to perform the following actions: • Monitor the contents of the firmware using applications and/or out-of-band mechanisms on the device under test (DUT). • Monitor events that can indicate attempted firmware modifications using applications and/or out-of-band mechanisms on the DUT. • Use server-side components to communicate with the sensors on the DUT, collecting the data and processing it to verify firmware consistency or to determine whether a mission is ongoing to modify firmware. • Present firmware health to an administrator using a security information and event management (SIEM) solution. Whenever a new security capability is integrated into IT operations there is a cost associated with purchasing the capability, integrating it into existing security processes, and training personnel to use the capability properly. Since BareMetal is intended for nonspecialists and its analysis is completed in less than two minutes, it can be added to the receiving and provisioning process with minimal impact both to staffing and provisioning time. This cost efficiency, along with the relatively inexpensive purchase cost of the BareMetal device, allows organizations to cost effectively improve the security of their IT system by introducing BareMetal into their supply chain risk management procedures. • Adam Fraser, Joe Tanen and Eric Egalite 1 ARM refers to a family of reduced instuction set computer based (RISC-based) processors designed and licensed by British company ARM Holdings. RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 21 FEATURE NEXT GENERATION EO/IR Detectors Electro-optical/infrared (EO/IR) system capabilities are continuously being expanded and improved. This is in part due to the development of high-performance focal plane array (FPA) technology. Raytheon Vision Systems (RVS) is actively advancing the state-of-the-art for new and discriminating FPA technologies in the 3–5 micrometer (µm) mid-wavelength infrared (MWIR) and the 8–12 µm long-wavelength infrared (LWIR) spectral regions by using a variety of semiconductor materials and FPA architectures. These include advanced III–V1 semiconductor strained-layer-superlattice (SLS) FPAs, II–VI2 semiconductor mercury cadmium telluride (HgCdTe) dual-band FPAs and uncooled bolometer FPAs using microelectromechanical systems (MEMS). Each of these FPA technologies address different mission requirements and are being developed to not only increase sensor capability and performance, but also to provide improved manufacturability and reduce costs. Advanced III–V Materials WIR FPAs with higher operating temperatures are advantageous for reducing the size, weight and power of cooled systems. For this reason, high operating temperature (HOT) FPAs are being developed based on molecular beam epitaxy (MBE) grown indium arsenide/gallium antimonide (InAs/GaSb) strained-layer-superlattice (SLS) bandgap engineered barrier device structures. The goal is to develop materials that have the producibility advantage of traditional III–V indium antimonide (InSb) technology, but the operating temperature advantage of HgCdTe. The InAs/GaSb family of SLS is the only known IR detector material with fundamental properties that provide a theoretically predicted higher performance than HgCdTe (lower dark currents at the same wavelength and temperature, with a comparable absorption coefficient). This SLS family has features whereby unique device architectures that provide performance advantages can be realized using multiple lattice-matched layers with a wide range of bandgap energy on a GaSb substrate as shown in Figure 1. These III–V semiconductors have greater latitude in process parameters (such as temperature) and tolerance to process-induced defects, and there is also a broader industrial base such that larger substrates and merchantsupplier MBE growth houses are available to produce the material and contribute to the technology development. Together these factors offer the promise of improved performance, higher yield and reduced cost for FPAs fabricated on SLS material. M 2.5 0.5 GaP Ga Ga Ga Ga Ga Ga Sb Sb Sb Sb Sb AlAs 0.6 2.0 Ga Ga Ga Ga Ga Ga Sb Sb Sb Sb Sb Ga Ga Ga Ga Ga Ga Bandgap (eV) Sb Sb Sb Sb Sb 0.8 AlSb 1.5 InP GaAs 1.0 1.0 0.5 1.5 GaSb GaInAsP Ga 0.47 In0.53 As GaInAsSb 3.0 InSb 5.0 10.0 InAs 0 5.5 5.7 2.0 5.9 6.1 6.3 In In In In In In As As As As As In In In In In In As As As As In As Interface As In In In In In In As As As As As Ga Ga Ga Ga Ga Ga GaSb Interface InAs Sb Sb Sb Sb Sb GaSb Ga Ga Ga Ga Ga Ga Sb Sb Sb Sb Sb Ga Ga Ga Ga Ga Ga Sb Sb Sb Sb Sb SiO2 6.5 Lattice constant (A) Figure 1. The semiconductor bandgap versus lattice constant graph on the left shows various binary compounds that can be used to create, for example, an InAs/GaSb strainedlayer superlattice (SLS) structure (middle) whose bandgap can be varied by the thickness of the individual layers. The picture on the right is a high resolution transmission electron microscopy (TEM) image of an SLS structure which shows the amorphous nature of the SiO2 passivation layer in contrast to the atomistic nature of the crystalline InAs/GaSb SLS. 22 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Dual-band FPAs Raytheon has developed an industry leading dual-band HgCdTe infrared FPA architecture (Figure 2) that is in production for advanced missile interceptor applications, and is being further refined and expanded as a third generation upgrade to existing tactical systems for ground and airborne applications. The availability of spectral information from a second spectral band enables the discrimination of absolute temperature and unique signatures of objects in a scene (Figure 3). When coupled with advanced signal processing algorithms, two-color infrared detection provides improved sensitivity compared to that of single-color devices. These advanced FPAs are necessary in order to improve acquisition, discrimination and the tracking of ballistic missile warheads, or the identification and engagement of tactical battlefield targets. This FPA architecture utilizes MBE-grown HgCdTe on 6 x 6 centimeter (cm) cadmium zinc telluride (CdZnTe) substrates, but there is also a significant development focus on using 6-inch diameter silicon (Si) substrates to substantially lower cost. Achieving the highest dual-band FPA performance, particularly for the LWIR band, is more challenging when using a Si 1 The III–V semiconductors are compounds composed of elements from the IIIA and VA CAS-standard groups of the periodic table or equivalently groups 13 and 15 based on the modern group-numbering standard. 2 The II–VI semiconductors are compounds composed of elements from the IIB and VIA groups of the periodic table based on the CAS group-numbering standard. These are groups 12 and 16, respectively, using the modern groupnumbering standard. FEATURE is illustrated in Figure 4, which compares the uncooled LWIR images of the Santa Barbara Mission taken with 640 x 480 and 2048 x 1536 pixel FPAs. Note that these images were taken at different times of the year so the details around the mission vary, e.g., the truck on the left in the top image was gone when the bottom image was taken. Unit Cell Indium Bump Contact Band-2 Absorber P-Type Cap Layer Band-1 Absorber CdZnTe Substrate Shorter Wavelength Longer Wavelength Figure 2. The left figure shows a schematic cross-section of Raytheon’s single-contact, single-mesa dual-band HgCdTe detector architecture, and the right shows a scanning electron microscope image of dual-band detectors with indium bumps on individual diode mesas. MWIR substrate due to the very large lattice and thermal mismatch between Si and HgCdTe that contributes to elevated material dislocation densities. Improvements in device design and material growth makes the goal of low cost dual-band HgCdTe FPAs on 6-inch diameter Si substrates attainable. eters which are fabricated monolithically on 200 millimeter (mm) Si read-out integrated circuit (ROIC) wafers. Over the last few years, this technology has been further enabled by Raytheon partnering with a high-volume commercial semiconductor company, Freescale Semiconductor, to fabricate the bolometers. Uncooled FPAs LWIR uncooled FPAs employing MEMS-based microbolometer structures are now widely used in both commercial and U.S. Department of Defense (DoD) applications. By its nature, uncooled technology is lower cost because it is operated at room temperature and can utilize simpler, smaller packaging without the need for a cooler. Additionally, it is fabricated on large area Si substrates using commercial manufacturing technology. Raytheon uncooled technology uses vanadium oxide (VOx) microbolom- Typical uncooled FPA formats use 640 x 480 pixels or smaller with a pixel size of 25 µm. Raytheon, in partnership with the Army Night Vision and Electronic Sensors Directorate (NVESD) and the Defense Advanced Research Projects Agency (DARPA), is also developing three mega-pixel-class uncooled FPAs with a 2048 x 1536 format for very large format, high resolution sensors. An example of the dramatic resolution improvement using this very large format FPA LWIR Figure 3. Example of imaging using a MWIR/LWIR dual-band FPA produced using HgCdTe grown on a low-cost Si substrate as part of an Army Night Vision and Electronic Sensors Directorate (NVESD) development program. The image from the MWIR band on the left shows transmission through the MWIR filter but not the LWIR filter, while the LWIR image on the right shows the opposite effect. Additionally, RVS in partnership with DARPA is developing wafer scale manufacturing processes to enable uncooled camera-on-a-chip technology as part of the Low Cost Thermal Imager – Manufacturing (LCTI-M) program. The goal of this effort is to dramatically lower the cost of this technology to enable wide use of infrared imaging technology and insertion in compact systems. Uncooled LWIR 640 x 480 Uncooled LWIR 2048 x 1536 Figure 4. The dramatic resolution improvement using large format FPAs is illustrated in the images above that compare an uncooled LWIR image of the Santa Barbara Mission taken with a 640 x 480 pixel FPA (top) with an uncooled 2048 x 1536 pixel FPA (bottom). Through these and other activities, RVS continues to advance the state-of-the-art in FPA technology to achieve higher performance, lower cost and smaller size EO/IR sensor systems. • S.M. Johnson and E.P.G. Smith RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 23 FEATURE QUANTUM COMPUTERS: Big and Small Q uantum information processing is enjoying a new level of excitement as researchers learn to engineer quantum systems. The Quantum Information Processing (QuIP) group at Raytheon BBN Technologies is tackling both the long-term problems of building tools for the design and analysis of large scalable quantum computers and the more immediate problems of implementing record-breaking, proof-ofconcept devices to demonstrate the power of quantum devices in computation, imaging and communication tasks. Introduction On a fundamental level, quantum computing is a quest to harness the ultimate processing power allowed by the laws of physics. On a practical level, it offers the promise of massive improvements in the time to solve certain problems of extreme import. Most famously, an implementation of Shor’s algorithm1 could factor large numbers with computational resources proportional to a polynomial function of the key length. This polynomial-time factoring capability would have huge consequences as it could enable attacks on many of today’s public encryption algorithms whose security relies on the need for an exponentially large amount of computing power to crack the encryption code. Other examples where quantum computing could have a significant impact include the use of an algorithm called Grover’s algorithm2 to speed up brute force search tasks and the development of exponentially more efficient algorithms for calculating the dynamics of complex many-body systems. Recent work by Raytheon has identified how quantum processors can improve imaging and communication capabilities both at optical and radio wavelengths. Quantum processors require completely new physical implementations, where quantum bits or “qubits” replace the traditional bits encoded as voltages in a complementary metal-oxide semiconductor (CMOS) circuit. Like classical bits, qubits have two logical states (“0” and “1”). However, they differ in that they can be manipulated into any of a continuum of superpositions, whereby they exist simultaneously in mixtures of the two states with a well-defined relative phase between them. These superpositions probabilistically collapse purely into “0” or “1” upon measurement (or readout) of the qubit. The power of quantum computation comes about when one maintains the superpositions during the entire algorithm, measuring the state of the system only to obtain the final answer at the end. Analogous to traditional computation, quantum computation requires a universal set of one and two qubit logic gates in order to perform any quantum processing algorithm. Also analogous to classical bits sent over communication networks, quantum systems can implement error correction codes through the use of large collections of physical bits to encode a single logical qubit. However, these codes must be implemented in very particular ways so as to avoid measuring the logical quantum information directly, which would destroy the superposition and thus the quantum advantage. In order to realize quantum computation, a technology must be able to perform a universal set of gates with sufficiently low error rates to be fault tolerant with suitable error correction. Additionally, one must be able to scale the technology to large systems of qubits, each with its own control and read-out circuitry. Quantum Computer Implementations There are several candidate qubit implementation approaches, each possessing its own set of challenges to obtain sufficiently low error quantum gates and scaling to system sizes needed for real-world applications. These include ionic atoms trapped by electric fields, neutral atoms confined by lasers, photons traveling through integrated circuits, nitrogenvacancy color centers in diamond, and electron spins in semiconductors. In addition, Raytheon, along with IBM, Northrop Grumman and several academic institutions around the world, is developing quantum processors in superconducting circuits using Josephson Junctions. Circuits comprised of superconducting metal and cooled below their critical temperature can support the dissipationless flow of electron pairs (Cooper pairs) and act in a quantum coherent manner. Josephson 1 Shor’s algorithm is a quantum computing algorithm, named after mathematician Peter Shor, that efficiently calculates the prime factors of an integer. 2 24 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Grover’s algorithm is a quantum computing algorithm, named after computer scientist Lov Grover, that efficiently searches an unsorted database. FEATURE Junctions are thin resistive layers fabricated into the circuits that provide a nonlinear behavior, allowing them to act as qubits. Information is encoded in the direction and pattern of electron current traveling through the circuits. Over the past five years, the superconducting approach has seen very significant progress, demonstrating one and two qubit logic operations with low error rates (<0.2 percent and <1 percent, respectively). One of the main reasons for this progress is that error rates are often driven by unwanted decoherence of the qubit (often decay into the “0” state) after a short period of time. These qubit lifetimes have recently improved by three orders of magnitude, to greater than 100 microseconds. This provides enough time to perform more than 1,000 operations and is thus sufficient for fault tolerant operation. Researchers are now beginning to focus on the challenges associated with hardware scalability. Raytheon is collaborating with IBM on a number of scalability topics as part of the Intelligence Advanced Research Projects Activity (IARPA) Multiqubit Coherent Operations (MQCO) program. Inset 1 in Figure 1 shows a superconducting chip containing three qubits and resonators that couple the qubits together and enable measurement, i.e., read-out, of the qubit state. The chip is put into a dilution refrigerator (large cylinder in Figure 1) which cools the chip to below 50 milli-Kelvin (-272.95 °C and just 0.05 degrees above absolute zero) where coherent quantum operations can be executed. Recently, Raytheon demonstrated gates with approximately a 0.2 percent error rate, approaching the fault-tolerant threshold for scalable computation. Current work is focused on the design and fabrication of an eight qubit device using a design scalable to much larger sizes. Quantum logic gates and the read-out of qubits for these superconducting devices is done by applying radio-frequency pulses at frequen- cies in the range 5–10 GHz. This requires that scalable quantum processors include flexible, reliable and high performance waveform generators of reasonable cost. Toward this end, Raytheon has developed the arbitrary pulse sequencer (APS) shown in Figure 1, Inset 2. The APS boxes provide 14-bit, 1.2 giga-samples per second (GS/s) analog output, allowing the sophisticated pulse shaping necessary for high fidelity gates and supporting sequences of up to 8,192 pulses. The Raytheon developed firmware for the APS boxes provides easy and rapid implementation of complex quantum gate sequences. Quantum Optical Communications In parallel to the superconducting quantum processor effort, Raytheon has been carrying out research on quantum optical receiver implementations with an objective of understanding and quantifying the ultimate limits of communication and imaging system information transfer using optical technoloInset 2 Inset 1 Resonators Qubits Figure 1. A chip (Inset 1) containing co-planar waveguide resonators and superconducting circuits serving as quantum bits (qubits) is cooled in a dilution refrigerator (blue cylinder in photo) so that coherent quantum operations can be executed. The customized arbitrary pulse sequencer (APS) device (Inset 2) is a high performance waveform generator developed by Raytheon BBN Technologies to control qubit experiments. RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 25 FEATURE gies. Through the Defense Advanced Research Projects Agency (DARPA) Information in a Photon (InPho) program, Raytheon has been exploring the ultimate information efficiency of light. This research involves identifying the maximum power efficiency, in bits per photon, allowed by quantum physics on a free space optical communications channel as well as in imaging systems such as laser radars (LADARs). So far, two important conclusions have come from this work: 1) the maximum bits per photon can be much greater than one when multiple spatial or temporal degrees of freedom are employed (though there is a clear trade-off between degrees of freedom used and photon efficiency); and 2) the maximum power efficiency (for a given number of degrees of freedom) is much greater than even the ideal limit obtainable with any current optical receiver approach such as direct, homodyne or heterodyne detection. Motivated by the theoretical result, Raytheon BBN Technologies proceeded to identify physical implementations of these quantum optical Quantum Computers: Big and Small receivers to demonstrate the ability to surpass the information transfer limits of current detection systems. An example of such a receiver is the green machine which can improve the photon efficiency for a binary phase shift keyed communication system from its current maximum of 1.44 bits/photon to a much higher, potentially unlimited, value. However, there is a fundamental trade-off which imposes a corresponding decrease in the rate of information transfer in a given bandwidth (spectral efficiency). Any loss or scatter in an optical receiver results in wasted power and thus a reduction in photon efficiency. Thus, one of the challenges of implementing optical receiver devices at the quantum limits of efficiency is the necessity for highly accurate alignment and low losses. Implementation in large-scale or fieldable systems will likely require implementation in integrated optical waveguide devices made from low loss material such as silicon. Raytheon collaborated with the optical nano-photonics group at Oak Ridge National Labs to fabricate and test an integrated silicon waveguide implementation of the green machine, shown in Figure 2. It is an eight input and eight output device containing 12 beam splitters and encompassing an area of approximately 10 square millimeters (mm2). By comparison, such a device implemented via bulk optics would require an area of approximately 300 square centimeters (cm2) and would likely not be capable of meeting the phase alignment requirements. One of the most interesting results derived from this effort was that ultimately devices with the computational power of a universal quantum computer will be required to reach the power efficiency limits possible using quantum optical communications and imaging methods. This is another interesting new potential application area for quantum processing, i.e., high performance military communications and imaging. Quantum Computer Tools and Programming As advances in the physical implementation of quantum processing devices have progressed, the need to develop high level tools to under- Optical Fiber Inputs B Beam Splitter P Phase Splitter Figure 2. A 10 mm2 silicon integrated optical circuit built collaboratively between Raytheon and Oak Ridge National Laboratory. This circuit can be used to process received optical communications at capacities well beyond the classical Shannon limit. 26 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY FEATURE stand and manage the complexity of large multiple-device systems has become apparent. For example, with quantum computation it becomes important to understand the impact of low-level device control issues on the fault-tolerance of larger multi- device systems and to be able to describe large and complex algorithms in a clear, compact manner, abstracted from the physical details of the machine implementation. Under IARPA’s Quantum Computer Science (QCS) program, Raytheon has developed a Quantum Functional Programming Language (QuaFL) specifically designed for implementing quantum algorithms. An important feature of QuaFL is the automatic inclusion of constraints imposed by the laws of quantum physics that govern the operation and error model of the quantum processing device. Like traditional functional programming languages, QuaFL provides familiar abstractions to free the programmer from thinking in terms of physical circuits, while at the same time guaranteeing that forbidden operations such as copying data, which is not allowed due to the no-cloning theorem of quantum mechanics, are reported as compilation errors. Also under this program, Raytheon BBN Technologies has done extensive work optimizing error correction codes used for quantum computing. In particular, analytic results on one of the best known quantum error correcting codes, the surface code, were extended to show that the surface code method is a favorable approach in terms of resource consumption and its implementation on realistic qubit architectures. This is an extremely important result in scalable quantum computation because the physical qubit resources required to implement logical qubits is a big driver in the complexity of a full quantum processor. It is also important because it allows optimization and resource estimation of systems that are much too complex to perform in the way they are done on the relatively small systems in laboratories today. The Future The development of quantum processors at a scale interesting to applications will be a long but exciting process. What is particularly exciting today is the rapid progress in the understanding and manipulation of certain physical qubit implementations, including the Josephson Junction superconducting circuits being developed by Raytheon BBN Technologies and other laboratories around the world. This progress has spawned new research focused on scaling these building blocks to large system implementations. Raytheon has so far focused its research on designing multiqubit architectures, developing scalable radio-frequency control and read-out electronics, developing programming languages to compile large-scale quantum algorithms, and finding interesting new applications of quantum processing in communications and imaging. Additional important and difficult challenges also on the horizon include reliable, large-scale fabrication of qubits and the efficient characterization and debugging of large-scale devices. Recent progress in these areas indicates that quantum processing will experience rapid development in the U.S. and around the world over the next several years and it is expected to eventually be adopted as a powerful and game-changing computing technology. • Zac Dutton, Ph.D., and Marcus Silva Contributors: Blake Johnson, Monika Patel, Saikat Guha, Colm Ryan, Thomas Ohki and Jonathan Habif We acknowledge support for this work from the IARPA MQCO program under contract W911NF-10-1-0324, the IARPA QCS program under contract number D11PC20166, and the DARPA InPho program under contract number HR0011-10-C-0162. E N G I N E E R I N G P R O F I L E FEATURE Zachary Dutton, Ph.D. Raytheon BBN Technologies Dr. Zachary Dutton has been manager of the quantum information processing business unit at Raytheon BBN Technologies since July 2012. His work focuses on improving communications and sensing techniques utilizing quantum optics effects. He was the BBN principal investigator (PI) on the Defense Advanced Research Projects Agency (DARPA) Quantum Sensors program, investigating quantum enhanced LADAR, and the DARPA Quiness program, focusing on developing optical quantum key distribution methods that achieve higher rates and continental scale distances. Additionally, he has worked on architectures for superconducting circuit based quantum computation in collaboration with experimental colleagues developing these systems. “Our customers are focused on investigating novel quantum effects seen in physics laboratories.” He states. ”We try to understand if and how they can enhance current communications, sensing and computation systems, and focus on the engineering challenges in realizing these enhancements. As a manager, I get to meet and interact with our customers on a regular basis to understand their goals and work with them to achieve those goals. And in my more technical role, I get to propose and research solutions to these difficult challenges.” Dr. Dutton received his doctorate in theoretical atomic physics from Harvard University in 2002. In his thesis work, he performed seminal work on coherent nonlinear optical effects in cold atomic ensembles and Bose-Einstein condensates, including electromagnetically induced transparency, slow light and coherent optical storage. He was a National Research Council post-doctoral fellow at the NIST-Gaithersburg and a staff physicist at the Naval Research Lab before joining Raytheon BBN Technologies in 2007. “My academic training involved the odd situation of working as a theorist in a primarily experimental group. I believe being forced to work in such close collaboration with experimentalists and having to analyze real experimental data (as opposed to ideal theoretical models) gave me a very pragmatic, problemsolving approach which has served me well throughout my research career. It has allowed me to quickly broaden to new topics and attack new problems. I believe this approach has even served me well in the business and management aspects of my current role, which requires quick decision making and decisive action based on the best available data, which can often be incomplete or approximate.” RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 27 FEATURE Particle Flow Filters to Solve Near IMPOSSIBLE PROBLEMS The EKF uses a linear approximation of the system dynamics and works well for certain applications, but it can give surprisingly bad accuracy for systems with difficult nonlinear or non-Gaussian noise dynamics (Table 1). Particle filters (PFs) have the promise of optimal accuracy for arbitrary nonlinear non-Gaussian problems, but at a huge cost in real-time computational complexity. A PF approximates the probability density of the state vector using numerical values at points in the state space (so-called “particles”), and hence it can represent highly non-Gaussian densities by using enough particles. A PFF moves the particles to the correct regions in the state space to represent the probability density accurately using physics rather than Monte Carlo simulations. It is much better to use 1,000 correctly chosen particles in the state space rather than 10 million randomly or poorly selected particles in the wrong locations. The PFF can be several orders of magnitude more accurate than the EKF for difficult nonlinear dynamical system problems that may even contain non-Gaussian noise (see Figure 1). In addition, the PFF is many orders of magnitude faster than standard PFs for three reasons: 1) PFFs use many fewer particles than PFs to achieve optimal accuracy; 2) the PFF software implementation is much faster than the PF implementation; and 3) PFF computations can be parallelized for efficiency. In particular, standard PFs require millions or billions of particles to achieve the same accuracy as the PFF for high dimensional problems (e.g., Figure 1). Systems engineers can exploit the particle flow filter in several ways: 1) lower system cost owing to less expensive sensors or less expensive computers; 2) achieve better system accuracy; 3) increase system capacity to track more targets or targets at longer range or stealthier tar- ITEM EXTENDED KALMAN FILTER (EKF) STANDARD PARTICLE FILTER (PF) PARTICLE FLOW FILTER (PFF) What is it? Linear approximation of nonlinear dynamics and nonlinear measurements Monte Carlo approximation of non-Gaussian probability density Exact computation of non-Gaussian probability density using physics rather than Monte Carlo simulation Estimation accuracy for linear Gaussian problems Optimal Optimal if you use enough particles Optimal if you use enough particles Estimation accuracy for certain (easy) nonlinear problems Nearly optimal Optimal if you use enough particles Optimal if you use enough particles Estimation accuracy for difficult Very poor nonlinear non-Gaussian problems Optimal if you use enough particles Optimal if you use enough particles Real-time computational complexity Extremely fast (even for high dimensional problems) Extremely slow for high dimensional problems Many orders of magnitude faster than standard particle filters for high dimensional problems Representation of the probability density of the state conditioned on the set of all measurements Mean and covariance matrix of Gaussian density Arbitrary non-Gaussian density using numerical values at N points in state space (so called “particles”) Arbitrarily smooth, nowhere vanishing, non-Gaussian density using particles Table 1. Attributes of the Kalman filter, particle filter and particle flow filter. 28 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY gets; 4) use much smaller computers which can be used in applications requiring less volume, less power or less weight, such as airborne or space-based sensors or systems requiring very compact computers for mobility or stealth; and 5) solve problems that were previously thought to be impossible to solve. The PFF is three to four orders of magnitude faster per particle because it avoids the bottlenecks of standard PFs, and, in addition, it uses three or four orders of magnitude fewer particles. For example, for a typical radar tracking problem the filter estimates the position and velocity of a ballistic missile, 107 VELOCITY ERROR METERS/SECOND) T he Raytheon particle flow (nonlinear) filter (PFF) provides superior system performance and lower cost for tracking, prediction, navigation, guidance, control, robotics, multiple sensor data fusion, autonomous decisions and learning, image processing, communications, weather forecasting, compressive sensing, multi-input multi-output (MIMO) communication systems, MIMO radar systems, MIMO navigation systems, cryptography, cyberwarfare, medical diagnosis, science and many other important applications. A filter is an algorithm that estimates the state of a dynamical system using a set of noisy measurements. For example, we use Kalman filters (KFs), and for nonlinear systems its extended Kalman filter (EKF) variant, to locate the position of your car using noisy range measurements provided by multiple Global Positioning System (GPS) satellites. KFs and EKFs were invented more than 50 years ago, and they are used for object tracking and estimation in essentially all modern radars, sonars, optical systems and other sensor systems. 106 105 N = 1,000 particles 100 Monte Carlo trials 20 dB SNR 104 Standard Particle Filter 103 102 101 100 0 Extended Kalman Filter Particle Flow 20 40 60 80 100 TIME (SECONDS) Figure 1. Particle flow filter beats the extended Kalman filter velocity estimation accuracy by an order of magnitude for long range radar tracking of ballistic missiles. hence, the dimension of the state vector is six. A standard PF typically requires 10 million particles to obtain optimal accuracy for a six dimensional state space, whereas the PFF needs only one thousand particles, for a savings of four orders of magnitude in computer speed. Moreover, the PFF is typically three to four orders of magnitude faster per particle computation than a standard PF, and therefore the net reduction in computer throughput is seven to eight orders of magnitude without parallel processing. This means that problems can now be solved that engineers thought were impossible to solve because the computer would be much too expensive or much too large for a given application using standard PFs. FEATURE ENGINEERING PROFILE Fred Daum Principal Engineering Fellow Standard PFs suffer from the curse of dimensionality and particle degeneracy, whereas the PFF solves these problems through particle flow. The root cause of the PF problem is Bayes’ rule, which is the computation of the probability density of the state vector using each measurement. In particular, the probability density after the measurement is the product of two densities: 1) the probability density of the state vector before the last measurement and 2) the density of the last measurement given the state vector. The basic idea of our new algorithm is to compute Bayes’ rule using particle flow equations borrowed from physics rather than the standard approach of multiplying two functions. The particle flow is designed by solving a partial differential equation (PDE), analogous to solving Maxwell’s equations for antenna design. In fact, our PDE is the first of Maxwell’s equations, i.e., the divergence of the electric field is equal to the charge density, and the rich history in physics of solving such equations is exploited to reduce the computational complexity of PFF computations. For example, we use incompressible flow and irrotational flow as well as Coulomb’s law to move the PFF particles. Incompressible flow is an excellent approximation for subsonic flight in air, which was invented by physicists and mathematicians more than 200 years ago, and it greatly simplifies the PDE used in fluid dynamics to design aircraft. Our PFF uses the exact same idea. However, filter designers do not need to solve PDEs in order to design PFFs. Rather, they can use several derived implementation methods (18 at latest count) to solve the PFF PDE equations, resulting in algorithms like the ubiquitous KF and EKFs that are easily programmed on computers. This approach is analogous to antenna designers who do not attempt to solve Maxwell’s equations from scratch, but rather open the handbook of antenna design and use the relevant solution with some good approximations (e.g., far field, narrowband, small aperture approximations). There are many different kinds of antennas, and each one uses a different set of approximations, which is analogous to our 18 distinct methods to solve the PFF PDE. Standard PFs attempt to repair the damage done by Bayes’ rule using Monte Carlo methods by resampling particles (i.e., throw away the useless particles and sample new particles to replace the bad ones), but with very limited success. This approach is analogous to a basketball player taking shots at the basket randomly with her eyes closed; if the ball misses the basket, then she takes another shot, and another, and another, as in a Monte Carlo method (e.g., Metropolis-Hastings). Such methods work for low dimensional problems, but they fail catastrophically for high dimensional problems, because there are so many (wrong) directions in high dimensional space; this is called the curse of dimensionality. In contrast, the PFF keeps its eyes on the basket and calculates the predicted trajectory of the particles using physics. Physics is much better than blind, random guessing. In summary, Raytheon’s PFF is applicable to a range of mission problems and can be expected to pay dividends in system performance and/or reduced complexity. • Frederick E. Daum is an IEEE Fellow and a Principal Engineering Fellow with Raytheon Integrated Defense Systems. He has been with Raytheon for more than 44 years. Daum is a distinguished IEEE lecturer and a graduate of Harvard University. He was awarded the Tom Phillips prize for technical excellence in recognition of his ability to make complex radar systems work in the real world. When asked about interests and what got him started along his career path, Daum talks about his time as an undergraduate in college, when he first heard about Raytheon, “I was told that I could work on interesting, diverse high-tech radar systems with Raytheon; this had great appeal for me, and it turned out to be completely true. I was lucky to be given challenging tasks and large responsibility from the very beginning of my career.” As a radar systems engineer, Daum developed, analyzed and tested real-time algorithms for essentially all the large long range phased array radars built by the United States in the last four decades, including Cobra Dane, the Precision Avionics Vectoring Equipment Phased Array Warning System (PAVE PAWS), Cobra Judy, the Ballistic Missile Early Warning System (BMEWS), the Terminal High-Altitude Area Defense (THAAD) system, the Relocatable Over-the-Horizon Radar (ROTHR), the Upgraded Early Warning Radar (UEWR) and the Sea-Based X-Band (SBX) Radar, as well as several shipboard fire control systems and air traffic control systems. He developed and tested algorithms in radar waveform scheduling, Bayesian discrimination, data association, discrimination of satellites from missiles, calibration of tropospheric and ionospheric refraction and target object mapping. Daum’s exact fixed finite dimensional nonlinear filter theory generalizes the Kalman and Beneš filters. Daum is elated to do research in nonlinear filters. “I get to work with the world’s experts in radar system engineering,” he states. “I have the freedom to try out new ideas, and I get to work on extremely interesting and challenging technical problems.” Daum has published nearly 100 technical papers and has given invited lectures at the California Institute of Technology, Massachusetts Institute of Technology, Technion (Israel) Institute of Technology and multiple other universities and research facilities in the United States and internationally. Fred Daum RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 29 FEATURE AUTOMATED LANGUAGE TRANSLATION Breaking the Language Barrier to Cross-lingual Information Access Accessing Information From Foreign Content More than half the content on the Internet is in a language other than English, and three out of four Internet users are not native speakers of English. Although much useful information — some of it critical to economic success and physical security — can be gleaned from these foreign language sources, the value of this information often decreases over time. This presents a challenge because current translation by humans is too slow and too expensive to provide the quick, reliable access to foreign language information that governments and businesses need. Foreign language translation is changing, however. Advances in automated language translation technology have opened the possibility of breaking the language barrier for both information access and in-person communication. Figure 1 illustrates the central role that automated language translation plays in enabling communication and information access across different languages. The goal of an automated language translation system is to ingest sentences in a source language and produce a correct, fluent, semantically equivalent sentence in the target language. History of Automated Language Translation Despite the difficulty of automated translation problems, early attempts were made to tackle it dating back to the 1950s. Figure 2 shows a timeline of the major milestones in the evolution of automated translation. The prevailing approach in the early decades was to analyze the structure of the input sentence and determine the possible senses of its ambiguous words, and then apply translation rules crafted by expert linguists to generate the translation. A drawback of this rule-based approach is a lack of flexibility for adding new translation rules and ensuring consistency with the existing rules. Moreover, using this approach to build a translation system for a new language pair requires a linguist who is an expert in both languages. Also, the process of writing the requisite set of translation rules is a slow, difficult and labor-intensive undertaking. These are major disadvantages. A data-driven approach to automated translation began in the early 1990s. Instead of specifying translation rules manually, this methodology uses a parallel corpus that consists of sentences from the source language along with their translations in the target language. Example sentence translations from the corpus are used to derive automatically a large set of translation rules between smaller units (e.g., words or phrases), together with an associated likelihood for each rule. The rules and likelihoods are then applied to translate a new input sentence from the source language. This approach, called statistical machine translation (SMT), revolutionized automated language translation by enabling translation systems for new languages and domains to be developed quickly and cheaply. With the advent of SMT, the need for linguists who are experts in two or more languages to design translation rules manually is no longer necessary. Translation rules are now automatically derived from sentences translated by bilingual speakers who are not necessarily linguistic experts. This improves development time and reduces translation cost. Early SMT models focused on learning the translations of individual words. Thanks to the increased availability of data and cheap computational power, more complex models that can learn the translation of phrases or syntactic structures are being developed. The current approach to SMT, shown in Figure 3, uses statistical models dependent on linguistic information and context to produce translations that preserve sentence structure. SMT is still a fledgling technology despite the significant advances made over the last two decades. Current research continually incorporates advances in machine learning theory and linguistic modeling to improve the state of the art in SMT technology. Automated Language Translation Challenges The automatic translation process is easy to SMT Research at Raytheon depict, but difficult to achieve. A general propBBN Technologies erty of all human languages is the prevalence of Research in machine translation started at ambiguity in the meaning of individual words Raytheon BBN Technologies in 2003. In two as well as in the relationship between parts of a sentence. Humans are usually very efficient at TWO-WAY INFORMATION TRANSLATION WORKFLOW FOR resolving these ambiguities when interpreting SOURCES HETEROGENEOUS DOCUMENTS SPEECH-TO-SPEECH linguistic input, often without being aware of their existence. They rely on past experience and the context surrounding the speech or text to perform the task. This knowledge is very AUTOMATED LANGUAGE TRANSLATION hard to model in a computer system. Without access to such knowledge, an automated language translation system still has to meet the BROADCAST AND SOCIAL HARDCOPY DOCUMENT challenges of selecting the correct translation MEDIA MONITORING TRANSLATION of a word, rearranging the translated words according to the grammar of the target language, and producing a correct and natural-sounding Figure 1. Automated language translation enables translingual communications and translation. information access. 30 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY FEATURE years, Raytheon established itself as a leading player in the field of language translation by leveraging its experience in statistical modeling for speech recognition. Most of the research was done under Defense Advanced Research Projects Agency (DARPA) sponsored programs that had a great impact in advancing SMT technology. The alignment of these programs to the major milestones in SMT evolution can be seen in Figure 2. Between 2005 and 2011, Raytheon BBN Technologies participated in the DARPA Global Autonomous Language Exploitation (GALE) program, whose goal was to develop technologies to absorb, analyze and interpret huge volumes of speech and text in multiple languages. Raytheon was consistently ranked top performer in the program’s official evaluations organized by the National Institute of Standards and Technology (NIST). Raytheon was also the top performer in DARPA’s Spoken Language Communication and Translation System for Tactical Use (TRANSTAC) program, which aimed to develop technology for real-time speech-to-speech translation from English to a foreign language and vice versa. As part of these and other research programs, Raytheon made several significant innovations to improve the state of the art of SMT. For example, Raytheon BBN Technologies developed a translation model that produces translations with improved semantic coherence by using information about the grammatical relationship between words that occur far apart in sentences. Raytheon also developed a procedure for combining the outputs of multiple automated translation systems to produce a better translation than any of the individual outputs. Pre-DARPA GALE and TransTac 1994 2000 Rule Based Word Based Phrase Based Language dependent Labor-intensive rules Requires expert linguists Case-by-case approach Source-Target Corpus Trainer Training Phase Syntax, Context, Semantics Statistical Model Input in Source Language Translator Translation Phase Output in Target Language Figure 3. Statistical machine translation uses a large collection of translated sentence pairs to develop statistical models that then translate source language text. Raytheon researchers have likewise developed techniques for detecting names and handling names properly in translations, and for using confidence scores on the alignment between phrases to improve the translation quality. Raytheon BBN Technologies is currently part of the DARPA Broad Operational Language Translation (BOLT) program. DARPA launched BOLT in 2011 to address the U.S. Department of Defense’s need for quick, reliable access to the large volume of foreign language information generated by users online. One of the program’s goals is to create SMT technologies that can correctly translate informal text generated by online users, which often contains spelling and grammatical anomalies. Another goal is to deal with the problem of communicating with non-English-speaking local populations in foreign countries in person. Raytheon researchers have made significant progress in the short time since the program started, in- GALE and TransTac 2006 DARPA BOLT 2012 Hierarchical, Syntax Driven Context, Semantics Driven Language independent Statistical modeling Automatic training on parallel corpus Rapidly portable Figure 2. Automated language translation approaches have evolved from initial rule-based approaches to more current statistical methods. This evolution has been helped, in part, by Defense Advanced Research Projects Agency (DARPA) program initiatives such as the Global Autonomous Language Exploitation (GALE) program, the Spoken Language Communication and Translation System for Tactical Use (TRANSTAC) program and the Broad Operational Language Translation (BOLT) program. cluding developing abilities to robustly process errors in input text, better model syntax and semantics, and improve the statistical models using neural networks. Advances in speechto-speech translation include modeling of a conversation’s context and detecting speech recognition errors during translation to limit any harmful effects on the translation output. The BBN team ranked first in the formal evaluations of all BOLT machine translation tasks. Raytheon BBN Technologies Automated Translation Solutions In addition to conducting leading-edge research in SMT, Raytheon BBN Technologies has created several turnkey solutions for both the government and commercial markets based on its translation technology. TransTalkTM, a two-way speech-to-speech translation solution, runs completely on a smartphone without the need to call a remote server. It currently supports translation between seven languages (including Arabic, Pashto and Dari) and English, and it has been deployed for testing in Afghanistan. The Multimedia Monitoring System (described in Technology Today, 2012, Issue 2, pp. 52–55) uses BBN’s SMT technology for some of the foreign languages it supports. The Multilingual Document Analysis and Translation System (MDATS) uses BBN’s optical character recognition and SMT technologies to translate Arabic document images into English. All these systems have been deployed in a number of government locations for 24/7 use. • Rabih Zbib, John Makhoul and Walt Andrews RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 31 FEATURE Optimization Algorithms for DECENTRALIZED PLANNING AND CONTROL Introduction Current U.S. Department of Defense (DoD) missions for unmanned vehicles typically require one dedicated pilot to control each remote vehicle. The DoD’s long-range vision is to do more with less; pushing for more autonomy in the appropriate phases of the mission. Its priorities include: • Developing trusted highly-autonomous decision-making systems that enable the replacement of, in whole or in part, current human-intensive functions in order to maintain a decisive combat advantage. • Pursuing technologies and policies that introduce a higher degree of autonomy to reduce the manpower burden and reliance on full-time high-speed communications links while also reducing decision loop cycle time. • Developing collaborative autonomous capabilities that enable a team of unmanned systems to coordinate their activities to achieve common goals without human oversight. • Developing algorithms that perform autonomous mission optimization under dynamic circumstances, including dynamic task reassignment. • Developing a decentralized system of heterogeneous unmanned systems relying on network-centric, decentralized control that is flexible in its level of autonomy. There has already been a significant amount of research done in the area of autonomous vehicle control for surveillance-type missions. Almost all of that research has dealt with centralized cooperative control, with little research addressing the decentralized control problem where multiple autonomous vehicles are allowed to collaboratively work together to achieve mission objectives. In fact, the development of decentralized cooperative planning and execution strategies remains an open area of research and is the focus of this article. 32 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Decentralized Planning and Control for Unmanned Aerial Vehicles In principle, decentralized control offers advantages over centralized control that include alleviation from single point of failure events, lower latency sharing of information between participants, and a more even distribution of the information processing and mission planning burden among participants. A relatively simple benchmark problem was created to help develop and evaluate different decentralized control algorithms and to help understand their advantages and disadvantages relative to each other and to centralized approaches. The benchmark problem was to develop a collaborative planning and control approach that utilizes unmanned aerial vehicles (UAVs) to provide: 1) continual surveillance over a region of interest; and 2) accurate tracking of all targets detected in the region. It was assumed that all UAVs were flying at the same fixed altitude. The UAVs were modeled as point- Start mass objects that moved on a two-dimensional fixed altitude plane and had a fixed minimum turning radius. The targets were either moving or stationary, and the UAVs did not know the target dynamics. The UAVs were tasked with collaboratively searching the environment for targets and tracking the detected targets. For each planning window, each individual UAV needed to dynamically determine which assigned tasks it should perform, in what order to perform the selected tasks, and what trajectory it should fly to accomplish its tasks. Each UAV’s planning and control algorithm needed to consider sensor field-of-regard constraints, vehicle kinematic constraints, communication bandwidth constraints and possible target dynamics. For this example, vehicles were assumed to operate in a decentralized manner. At each time step, each UAV independently executed the same set of tasks as shown in Figure 1. Each Move UAV Receive neighboring UAV positions, current trajectories, sensor characteristics, uncertainty maps, and sensed target maps Score UAV assessment of world Small Score? No Create fused target picture and updated search uncertainty map, i.e.,i generate UAV assessment of world End Update time t = t +Δ t new Yes Solve cooperative search and track optimization problem over planning horizon Update UAV task assignment and trajectory Figure 1. Each unmanned aerial vehicle (UAV) starts with an initial search and track plan. Then each UAV executes the same set of dynamic planning tasks at each new performance assessment time step using its own and neighboring UAV sensor information. If the UAV’s assessment of the current plan is poor (indicated by a low score), then it executes a replanning set of tasks to change the plan and improve the predicted performance. We note that the start and end designations clarify the starting and ending points of the decision loop at each time-step. FEATURE UAV created its own assessment of the world, based on on-board sensors and communication with neighboring UAVs. Each UAV then determined whether its current plan moving forward was still appropriate, based on its assessment of the world. If it was not appropriate, then the UAV planning software was used to solve a coupled tasking and route planning optimization problem for itself and its neighbor UAV. The solution to this problem resulted in updated tasking, including new flight routes for itself and each neighboring UAV. Each of the UAVs might determine different solutions as compared with their neighbors. This is due to the fact that each UAV might have a different perspective, and hence assessment of the world. Currently, this solution mismatch is rectified when each UAV receives information from neighbor UAVs. Future research will involve incorporating alternative deconfliction approaches. The collaborative UAV search and track problem is a generalization of a standard vehicle routing problem (VRP). While there are many variants to the standard VRP, the general form considers m vehicles starting at a depot and tasked with delivering goods or services to a set of n customers. Each customer has a certain required demand, and each vehicle has a maximum capacity. The VRP is known to be NP-hard1, and thus by extension the UAV planning problem is NP-hard as well. To efficiently develop a solution to the UAV search and track optimization problem, a hybrid set of algorithms is used that combines both greedy randomized adaptive search procedures (GRASP) and simulated annealing (SA) techniques. GRASP is a multistart local search procedure, where each iteration consists of two phases; a construction phase and a local search phase. In the construction phase, interactions between greediness, i.e., moving the solution in the local direction that yields the largest performance improvement, and randomization, i.e., moving the solution estimate in a random direction, generate a diverse set of quality solutions. Then in the local search phase, the state space around the solutions generated in the construction phase are further optimized. SA is a method to find good-quality solutions to optimization problems by using a process that mimics the cooling process of metals. At each step, a current solution is perturbed. If the perturbation results in a better solution, then the current solution is replaced. If the perturbed solution is worse than the current solution, then the perturbed solution might still replace the current solution with a probability based on the distance between the current and perturbed solution values and the current temperature parameter used in the annealing process. As the method progresses, the temperature parameter is lowered, making it more and more unlikely to replace the current solution with a worse perturbed solution. For the hybrid GRASP-SA method, GRASP is used to determine the (near) optimal task assignment for the UAV and the SA method is used to determine the (near) optimal route that the UAV should fly to accomplish its tasks. The best solution over all of the GRASP multistart iterations is retained as the final solution. A complete solution, for a given UAV, consists of the tasking and flight path for that UAV, as well as the tasking and flight path of that UAV’s neighbors. The flight path trajectories are calculated over a selected planning time horizon. The hybrid GRASP-SA method as applied to the UAV surveillance and track planning problem is based on the assumption that only one task can be performed by a vehicle over the entire planning horizon. In reality, this is not the case. There are many instances when a UAV is assigned a task but is unable to perform that task during certain sub-intervals of the planning horizon because, for instance, the target to be tracked is not in the field-of-regard of the UAV’s sensor. To account for these taskfree sub-intervals, an additional method, the collection opportunity update (COU) method, was implemented that evaluates the GRASP-SA solution and determines where in each UAVs trajectory additional tasks can be performed, thus improving the quality of the solution. Simulation Results A simulation of UAVs performing a surveillance and tracking mission over an urban area was developed to test the decentralized planning and control algorithms. The GRASP-SACOU optimization algorithms were coded in C++ and inserted into a simulation environment that provided target and UAV kinematics, a scenario laydown, a display, and data 1 An NP-hard problem is a class of computational problems that are at least as hard to solve as the hardest problem that can be solved in polynominal time. logging and analysis routines. For comparison to the baseline UAV planning approach (a decentralized, cooperative approach), two other solutions were simulated; a centralized planning approach and a decentralized selfish approach. The centralized approach collects all UAV information at a central location and then generates all UAV tasks and flight paths using this information. Clearly, this approach is the most communication bandwidth intensive of all the approaches, but its access to all UAV sensor and tasking information make it the solution with the best task planning performance. The selfish approach allows individual UAVs to plan their own actions as in the baseline approach, but information from neighboring UAVs is not shared and the UAVs develop independent, uncoordinated tasking and flight plans. Two new metrics were developed to measure performance. The cost of decentralization is a measure of the solution quality of the decentralized approach versus a centralized approach. The price of anarchy metric compares the solution quality between the selfish and the cooperative approach. In Figure 2, we show the difference in solution quality before and after the COU algorithm. The figure represents a top-down view of a simulated urban environment. The gray rectangular objects represent the tops of buildings. The winged objects that have numbers near them and a curve extending from them represent the UAVs. The curves represent the projected flight path over the planning horizon; red segments indicate that the UAV is performing a searching task, a green segment indicates the UAV is performing a tracking task. The black outlined square, extending from each UAV, represents its sensor footprint. The motorcycles and cars represent the targets, and the light and dark blue colored background represents the composite probability of successful search regions. Light blue indicates a greater than 90 percent probability of that region being successfully searched, and dark blue indicates a greater than 95 percent probability. The GRASP-SA solution, shown on the left of Figure 2, shows the UAV route plans at one particular time step without the COU algorithm applied. UAVs 2 and 4 are tasked to search for targets, while UAVs 1 and 3 are tasked to track a previously detected target that is moving downward. It can be seen that RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 33 FEATURE Optimization Algorithms for Decentralized Planning and Control GRASP-SA GRASP-SA-COU 4 2 4 1 3 2 1 3 Legend UAV Computed Surveillance Route UAV Computed Track Route Identified Objects of Interest Unidentified Objects of Interest Current UAV Field of Regard Current >90% Probability of Successful Search Region Current >95% Probability of Successful Search Region Figure 2. UAV sensor utilization is improved using the GRASP-SA-COU approach (right) versus the GRASP-SA approach (left). The GRASPSA approach switches UAV 1 and 3 trajectory tasking from track to surveillance based on an estimate of when the target being tracked will no longer be in the UAV’s field of regard. the UAV 1 and 3 trajectories will not keep the target in their fields of regard and therefore will not be able to maintain a track over their entire trajectory planning horizons. for those UAVs having the same tasking. The closer the flight paths are to each other (from the centralized and decentralized approaches), the lower the cost of decentralization. The trajectories for the UAVs, with the COU algorithm applied, are shown on the right in Figure 2. None of the UAV trajectories change. However, UAVs 1 and 3 have modified their tasking so that once the extrapolated target position is no longer in the field of regard of their sensors, the tasking is changed to search, resulting in better usage of UAV resources. Figure 3 illustrates the comparison between solutions derived from the decentralized cooperative approach (left) and centralized approach (right), at a given time. The decentralized solution determines that all four UAVs should be in search mode over the complete planning horizon. By contrast, the centralized solution determines that three of the four UAVs should execute only tracking tasks and the fourth UAV should only perform surveillance at the end of its trajectory. Hence, the resulting cost of decentralization metric at this time is high. The cost of decentralization metric compares the solution produced using a centralized approach with the solution produced using a decentralized approach. The measure computes the normalized distance between trajectories 34 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY The cost of decentralization metric compares the solution produced using a centralized approach with the solution produced using a decentralized approach. FEATURE The price of anarchy compares the solution produced from a cooperative approach with a selfish approach. The measure computes the normalized distance between trajectories for those UAVs having the same tasking. This is one way to measure the benefit of cooperation, i.e., the benefit of sharing information on detected targets and search uncertainty. Figure 4 shows simulation results comparing the decentralized cooperative approach solutions (left) and the selfish approach solutions (right). There are significant differences in both the UAV trajectories and tasking and therefore the price of anarchy metric is large. On average, the selfish approach produces an 8 percent worse sensor resource utilization (based on a specific objective function) than the decentralized cooperative approach, primarily due to the lack of information exchange between UAVs when using the selfish approach. Summary The DoD is investigating autonomy as a means of lowering the manpower required to conduct missions. Decentralized cooperative control methods, such as the approach outlined in this article, provide starting points for further autonomy research and testing, eventually allowing the DoD to increase the amount of mission planning and execution done by machines and freeing operators for higher-level supervisory control to ensure broad mission objectives are being met. Decentralized Cooperative Approach Centralized Approach 3 4 2 2 3 1 1 4 Legend UAV Computed Surveillance Route UAV Computed Track Route Identified Objects of Interest Unidentified Objects of Interest Current UAV Field of Regard Current >90% Probability of Successful Search Region Current >95% Probability of Successful Search Region Figure 3. A comparison between the decentralized cooperative approach and the centralized approach shows significant differences in solutions, resulting in a large cost of decentralization metric. On average, the centralized approach yields a 19 percent improvement in sensor resource utilization as compared with the decentralized framework. Decentralized Cooperative Approach Selfish Approach 1 1 Rather than a dramatic shift, it is expected that the implementation of autonomy will follow a gradual path, starting out as intelligent decision aides and performing lower-level mission execution functions, all with operators tightly controlling all critical decisions. As the DoD’s experience and confidence using autonomous methods increases, it is expected that additional control will be performed by machines, allowing humans to allocate more time to defining top-level mission objectives and supervising mission execution. • Michael J. Hirsch, Ph.D., and Daniel Schroeder 2 2 4 4 3 3 Legend UAV Computed Surveillance Route UAV Computed Track Route Identified Objects of Interest Unidentified Objects of Interest Current UAV Field of Regard Current >90% Probability of Successful Search Region Current >95% Probability of Successful Search Region Figure 4. A comparison between the decentralized cooperative approach and the selfish approach shows there are some differences in solutions, resulting in a large price of anarchy metric. On average, the selfish approach produces a sensor resource utilization 8 percent worse than the decentralized cooperative approach. RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 35 FEATURE Partially Observable DECISION PROCESSES Decisions associated with a known or observable condition are based on facts from direct observation. For example, a normal pedestrian decides to observe the stoplight before proceeding to cross the intersection. For a blind pedestrian, however, the stoplight is only partially observable, so the decision is to listen for traffic and other pedestrians before proceeding. Listening infers the stoplight state based on indirect but related observables. Inference in a partially observable process is known as belief. Belief is the probability of being in a state and serves as a surrogate for fact when indirect but related observables must be used to infer state. More often than not, whether in sports, business, medicine, warfare, etc., real-world decisions are based on belief rather than fact. This article describes a belief-based method that Raytheon uses to optimize decision making in solutions we provide to customers. Partially Observable Markov Decision Processes (POMDPs) ecision making can be defined as a sequence of actions taken over time for the purpose of producing a desired goal. The important information of a sequence’s past history is often captured in the present state of the system (e.g., the confidence associated with a prioritized intelligence or high-payoff revenue tip), and in these cases only the current state is needed to determine the best action for transitioning to a future desired state. The formal model used to represent such a system is a step-wise stochastic sequence known as a Markov decision process (MDP). D 10 CEE D 9 PRO 8 7 VALUE 6 5 4 3 A completely observable MDP (COMDP) assumes that the state of a system (e.g., the color of the stoplight) at any time is known to the decision maker. Assigning reward (cost) for the known state attained from a decision immediately determines the best decision as the one with the highest reward (least cost). In a partially observable MDP (POMDP), the decision maker has only belief based on indirect observables (e.g., traffic and pedestrian sounds) with which to infer the state. Since belief is the probability of being in a state it can be any real number in the unit interval. So, while a COMDP typically has a finite or countable 36 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY 2 1 1 0.9 0 0.8 LISTEN 0.05 0.7 0.15 0.6 0.25 0.5 0.35 0.4 0.45 RED Belief 0.3 0.55 0.2 0.65 0.75 GREEN Belief 0.1 0.85 0 0.95 Figure 1. LISTEN is the selected action (plane) for belief states valued 0. PROCEED, indicated by separately colored bands of equal value, is valued non-negative for belief state pairs (GREEN 0.4, RED ~ 0). High value to PROCEED is only attained at near certainty of GREEN which is obtained from listening to traffic flow. FEATURE number of states, a POMDP has a continuously infinite number of possible belief states. Belief value is introduced to overcome the difficulty of belief cardinality in solving a POMDP. As in a COMDP, a reward is assigned for the value of belief state certainty (unit interval end points) attained from a decision. Given N states, the Nvector of state rewards for each decision defines a hyper-plane in N-dimensional “value” space that maps underlying belief into belief value. Solving a POMDP amounts to stepwise value iteration, successively estimating the maximum probable belief from observables at each step. After a finite number of steps, the process results in optimal decision hyper-planes that intersect to form a piece-wise linear convex surface known as the POMDP policy. For any belief, the POMDP policy dictates the best decision to attain a desired state. The POMDP model of the blind pedestrian’s optimal decision selection includes three stoplight states (GREEN [G], YELLOW [Y], RED [R]), two decisions (LISTEN, PROCEED), rewards (near 1 [0] for a good [bad] decision in a state) and observables (heavy, medium, or no traffic flow given states G, Y or R, respectively). The model’s transition functions consist of conditional probabilities associated with transitioning from one state to another given a decision. The model’s observation functions consist of conditional probabilities of an observable (sound) occurring having attained a state from a decision. Figure 1 illustrates the optimal decision policy that results from solving the POMDP. Since belief is a distribution of probability over three states, only two need be considered; in this case R and G, i.e., Y = 1 (G+R). The decisions, listen and proceed, are represented by two intersecting planes in three dimensional value space that map the belief state ordered pairs (R, G), 0 R + G 1, into belief values between 0 and 10. To visualize the blind pedestrian’s POMDP policy space, it is sufficient to consider (R, G) belief ordered 1 Jet Bridge Entrance Jet Bridge Entrance Camera Camera Greatest Risk Pedestrian Other Destination Entrance Other Destination Entrance Pedestrian Figure 2. Simulation snapshot of two active jet bridges and two independent cameras observing approximately 150 passengers. pairs whose component sums are less than or equal to 1. As evident in the diagram, only for belief states with R near 0 and G well above 0.5 does the policy highly value a decision to PROCEED. Autonomous Threat Assessment and Course of Action Applications Protecting jet bridges1 from a suspected terrorist is an unclassified, International Traffic and Arms Regulations (ITAR) compliant Anti-Terrorism Advisory Council (ATAC) scenario illustrating the design and operation of a POMDP that provides optimal course of action (CoA). The mission is to provide airport waiting area security to prevent unauthorized A jet bridge is an extendable bridge for loading passengers onto large commercial aircraft. access to one or more jet bridges. The waiting areas are viewed by one or more cameras with narrow fields of view (FOV) that cover only a portion (approximately 20 percent) of the entire area, and this FOV is POMDP controllable (i.e., the application can decide where the cameras point). In addition to pointing the cameras, the POMDP has two additional decision options: • Interdict a particular passenger before he or she gains access to the jet bridge. • Close the waiting area door when interdiction is not possible (threat is too close or threat assessment decision was made too late). RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 37 FEATURE Partially Observable Decision Processes TRUTH 2 INITIALIZE EEI C Declared “YES” 1 N Sensor Inputs Improve Belief for EEI C 1.00 Y Probability Query B 0.50 N Query C 1.75 0.50 0.25 N 0.00 0.96 A B D E F G H I Query Y Query D Y 5 Query E Contribution 1.00 0.50 Contribution N N 1.75 3 0.50 0.25 0.00 0.50 A B C D Y EEI D Highlighted Query Query F Query G Action 0.50 Action Value N E Tree Evaluation Identifies EEI D as the Highest Contributor Y 0.50 N 20 15 10 5 0 4 A B C D E Query Y POMDP Indicates EEI D now has Highest Benefit The specifications are in the form of intelligence requests (IRs) which may be prioritized, i.e., prioritized IRs (PIRs), and can be viewed as questions to be answered. PIRs are decomposed into essential elements of information (EEIs), some or all of which are needed to answer (or satisfy) the PIR. The EEIs — when decomposed to their lowest level — represent individual pieces of information that can be provided by a sensor. Often, these EEIs can be depicted as a decision tree, where each individual EEI belongs to a decision hierarchy designed to answer the original PIR. Action Query D Query I N 0.50 True - False True 0.55 0.45 1.00 1.75 Probability False 0.50 0.25 0.00 True State False Figure 3. Hierarchical POMDP determines at each step which questions, if any, can be declared and which make the largest contribution and benefit to the decision process. The process is continued until all questions are declared or the state is deemed acceptable. The POMDP uses the camera observations to generate a belief that each passenger is in a particular state, e.g., a terrorist. The belief is a probability distribution across all possible states. Based on the belief distribution, the POMDP decides on a CoA: either specify what parts of the waiting area to view next or take direct action against a passenger. The jet bridge mission has been simulated (Figure 2) in a stressing scenario involving approximately 150 pedestrians (represented by aqua dots) moving in the security area (background grid) and two independently controllable cameras (white dots) protecting two jet bridge entrances (red dots with range rings). Each pedestrian has a destination (one of the six red dots on the screen) out of the security area and moves toward that destination with random speed but with some wandering (a random variation on the direct path). One of these pedestrians is a terrorist. At any given time, the POMDP identifies (red box) which pedestrian is the greatest risk, although this risk may not be large enough to warrant further action. Testing shows that the POMDP does identify the terrorist every time; in about 85 percent of the cases this identification occurs in time for the interdiction to be performed (the lowercost option). The POMDP will autonomously decide to collect additional observations until 38 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY the belief is sufficient to trigger a CoA. POMDPs can also be applied to control multifunction sensors where several mission tasks will compete for sensor resources. Typically, this arises in sensor systems that can perform both surveillance and fire control functions, such as the F-15 radar and the predator multispectral targeting system (MTS) electro-optical system. In the course of a mission, these systems and their operators will be faced with decisions that require balancing the need to perform surveillance across a large area to maintain situational awareness and the competing needs inherent in a particular CoA such as dwelling on a particular detected entity in order to assess threat suspicion, tracking entities that are declared suspicious and obtaining additional targeting data to support other systems, such as weapon systems, that are used to counter a declared threat. Intelligence, Surveillance and Reconnaissance Applications The POMDP technique can also be applied to pure intelligence, surveillance and reconnaissance (ISR) sensor missions, i.e., missions having no follow-on fire control or weapon phases. The ISR process begins with a top-level commander specifying what information is needed to make ongoing command decisions. A notional PIR decomposed into its EEI decision tree is depicted on the left side of Figure 3. This particular tree is a fictitious example but is typical of an actual PIR and its associated EEIs where the consequence of a poor assessment is extremely serious but refining (improving confidence in) the assessment is potentially very costly. POMDPs can be constructed for each statistically independent EEI to help decide whether to declare the EEI question true or false or to gather more information, i.e., task an appropriate sensor that can provide additional information about this EEI. The belief states shown on the left side of Figure 3 capture the current confidence that the EEI question is true or false. With each new piece of information collected (which can be either positive or negative), the POMDP transitions the belief state from its current value to a new value that reflects the new information gained from the sensor collection. These individual POMDPs are rolled up into the overall PIR confidence level shown on the bottom right of Figure 3 based on their decision tree hierarchy. Autonomous Dynamic Tasking Applications Autonomous dynamic tasking (ADT) is a class of techniques and methods that optimize, and continually adjust, the execution of a set of tasks or activities based on the time-dependent relative importance of tasks. ADT has applications in the Department of Defense (DoD) and Intelligence Community (IC) for executing missions, as well as in commercial industries. An example of the latter is a commercial satellite imagery provider’s transition from quality of service (QoS) to revenue-based scheduling offered by POMDP value optimization. Paying customers select the desired image quality from a menu of cost-ranked options, and the highest FEATURE 44.20 Do ADT 44.10 Value 44.00 43.90 PPT ADT 3.80 Do ADT 43.70 43.60 0.0 0.2 0.4 0.6 0.8 1.0 Belief Figure 4. Two-state policy for executing a dynamic task in lieu of pre-planned tasking based on the belief in a high-payoff tip. paying customer receives the highest QoS through satellite spatial and temporal performance scheduling. However, QoS may be deliberately compromised if the provider acts on speculative high-payoff imaging opportunities (e.g., a sporting, political or major weather event such as a hurricane). Given a speculative tip, the ADT POMDP computes a policy for either adjusting pre-planned tasking (PPT) to accommodate the potential high-payoff event or not; the goal being to optimize revenue based on belief that the speculative event will occur and that coverage of the event will result in a substantial payoff. Figure 4 is an example of a policy consisting of two states, revenue gain and loss, and two decisions, ADT or PPT, depending on the confidence (belief) associated with a speculative tip. The POMDP decisions are represented by lines (one-dimensional action hyper-planes) intersecting in a two-dimensional value space. Value is the iterated expectation of the reward based on task priority ranking. The POMDP policy selects the decision associated with the line of maximum value for any belief. The ADT line has maximal value for tip confidence above approximately 0.55. Thus, only a relatively high confidence tip warrants sufficient revenue gain to override pre-planned tasking. Nonetheless, the POMDP policy suggests a strategic shift to a business model that integrates consumer-based QoS and provider-based revenue optimization. Future POMDP Application Areas The application of POMDPs to support critical decision making and actions is ubiquitous; ranging from autonomous threat detection and course of action missions to ISR mission planning to revenue-based QoS customer resourcing. New and promising applications of POMDPs to game-theoretic strategy formulation within Raytheon have been developed and successfully implemented, and new application areas continue to be researched. • Kenneth Moore, Ph.D., and Robert Vitali E N G I N E E R I N G P R O F I L E FEATURE Kenneth Moore, Ph.D. Director, Algorithms and Intelligent Systems Dr. Kenneth L. Moore has more than 33 years of experience in aerospace and defense industry business and technology leadership, program management and engineering. He has been the technology area director for algorithms and intelligent systems at the Raytheon Space and Airborne Systems business since 2007. As both director and subject matter expert, he contributes to solutions and oversees independent research and development (IRAD) investment definition and execution associated with mission and system analysis, modeling and simulation, concept of operations development and intelligent real-time algorithm development for airborne and space-based intelligence, surveillance and reconnaissance (ISR), cognitive electronic warfare (EW), on-board multi-intelligence (multi-INT) fusion and autonomous decision and control. “Success at Raytheon requires a balance between customer exposure, business pursuit and technical excellence,” Dr. Moore states. “The requirements of Department of Defense (DoD) and intelligence community (IC) customers are constantly changing as are their financial priorities. Leadership and technical excellence is recognized and rewarded when associated with high-priority customer problems.” Dr. Moore’s involvement with customer challenges over the past 15 years began with space-based missile defense and surveillance and has evolved to tactical airborne automatic target detection, identification and tracking, autonomous payload processing decision and control solutions associated with actionable information, multi-INT resource management and adaptive/cognitive strategy. Initially focused on counter terrorism and insurgency, he has transitioned his mission focus to counter anti-access/area-denial (C-A2/AD), stand-in EW strike, space-based ISR and space protection and situational awareness. He talks about, technologically, what a great time in history it is to be working on research and innovation: “Modern computing and networking have advanced to a point where decades of computationally overwhelming optimal control and decision solutions can now be reduced to practice with common families of algorithms tailored to applications that advance human reasoning.” RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 39 LEADERS CORNER The Raytheon Technology Leadership Council William F. Kiczuk (Chair) Steve Cummings, Ph.D. Chief Technology Officer (CTO) and Vice President, Corporate Technology Vice President, Technology Development and Execution, Space and Airborne Systems John Zolper, Ph.D. (Co-chair) Mark Hebeisen Vice President, Research and Innovation Technology Today spoke with Technology Leadership Council (TLC) members about how Raytheon research and technology is managed and the roles and responsibilities of its technology leaders. How does the TLC operate? Bill K.: Raytheon provides leading-edge, innovative technologies to our customers to ensure mission success, and the TLC manages the strategies that ensure the correct technologies are being developed and matured. As TLC Chair, I work with technology leaders across Raytheon to develop the company’s technical roadmaps and oversee the execution of the company’s research and technology initiatives. The TLC prioritizes Raytheon’s technologies based on our customers’ needs and our business plans and is supported by technology area directors (TADs) and champions. TADs and champions engage with the Raytheon technology network participants to assess our technology portfolio and identify technology trends, disruptions and innovations that will continue to differentiate Raytheon and our products. The company’s technical roadmaps integrate hundreds of different activities spread across numerous technology focus areas and include contract research and development activities (CRAD), independent research and development activities (IRAD) and university and industry partnerships. The roadmaps are reviewed and updated every year by the TLC, TADs, and technology champions to ensure the technology maturation strategies depicted in the roadmap are executable and provide the required technologies at the required times to support the mission needs of our customers. 40 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Strategic Architecture Director and Technical Director, Integrated Defense Systems What excites you about technology at Raytheon? Bill K.: I’ve been involved in Raytheon technologies for more than 30 years in different businesses and at corporate in my current role as CTO. I am continually impressed with the breadth of technologies being investigated and developed. Raytheon’s technology portfolio is always changing, with new areas emerging every year that have the potential of providing major improvements to our existing products or of being disruptive and providing a path to a whole new way of performing a mission. Whether the technology is a new radio frequency (RF) semiconductor device, a high power laser, or an advanced analytics algorithm, Raytheon is constantly investigating new technology areas and how these new technologies can be advantageously applied to our products and customer missions. I find the constant learning required to keep pace with these new and emerging technologies very exciting. Also, my frequent interaction with our talented and dedicated researchers and technologists is very rewarding. There is an excitement and energy you get from talking with these researchers and learning about their technology. What is the role of a business technical director (TD) and what are your day-today responsibilities as a TD? Mark H.: Within each business, the TD is responsible for the over-arching technology strategy for their business and is responsible for driving innovation, technical excellence, and technology development and maturation. The TD’s responsibilities within the business include IRAD planning and execution, coordination of CRAD capture activities, fostering of university and small company research efforts, and supporting our intellectual property (IP) Marty Rupp Technical Director, Missile Systems Brad Whittington Capabilities and Technology Director, Intelligence, Information and Services and legal teams to ensure our IP is properly developed and documented. Each TD is also a member of the TLC that is responsible for the leadership and coordination of technology efforts across the company. The TD is the primary point of contact within the businesses for supporting cross-Raytheon technology integration efforts. In addition to these responsibilities, each TD may have other business-specific responsibilities. For example, at Integrated Defense Systems (IDS), I also serve as the director of the strategic architecture engineering group. In this capacity, I lead a team of product-line chief engineers, technical directors and industry-recognized subject matter experts, many of whom are top engineering fellows. Hence, at IDS, the TD not only champions the technical strategy for the business, but also ensures flawless execution of the engineering content on new development and ongoing production programs. The TDs at the other businesses also have unique business-specific roles and responsibilities per the preferences of their leadership teams. How do the business TDs collaborate? Steve C.: The business TDs interact in a number of ways, both formal and informal. First, corporate events such as Technology Integration Week (TIW), monthly TD meetings chaired by the CTO, and technology focus area reviews provide formally scheduled opportunities for the TDs to collaborate, especially on companywide efforts and initiatives. Less formally, the TDs cooperate to support each other’s business needs through the formation and staffing of proposal and architecture review teams and other sharing of technical and programmatic expertise. Quite informally, the TDs correspond throughout the year via email and phone The Technology Leadership Council oversees Raytheon research, collaboration and technology opportunities and is responsible for developing and executing an integrated technology and research strategy for the company. The TLC is chaired by the Raytheon Chief Technology Officer with the technical directors from each Raytheon business as members. calls on opportunities such as innovation ideas, the sharing of IRAD results, and discussions on coordinating IRAD projects between businesses. How do you find and nurture innovation? Brad W.: As a world-class aerospace defense company, innovation not only invigorates and excites our workforce, it drives our business growth — especially in a budget constrained environment that seeks the typically affordable gains of innovation versus the generically expensive gains of invention. Thus, Raytheon spends significant resources at both the corporate and business level to drive and leverage innovative employee ideas. At the corporate level, the Identify, Develop, Expose, Action (IDEA) program and the Raytheon Innovation Challenge (RIC) encourage employees to submit innovative ideas that can lead to funding, customer interaction and leadership opportunities. Other corporate activities such as TIW and the Fellows workshop drive real-time innovation by assembling Raytheon’s technology leaders at a single location for presentations and working groups on technology planning and assessments as well as innovation. Each business also has its own methods and programs for identifying and nurturing innovation; all focused on setting up an efficient process for our technologists and engineers to get their ideas out, obtain technical feedback, and, potentially, obtain funding for further investigation. The corporate and business-specific initiatives are important and effective ways to identify and nurture innovation. However, the largest innovation creating process at Raytheon continues to come from the engineer’s interaction with their peers and mentors. Activities as simple as buying a younger employee lunch, asking a mentor a question at the water cooler or raising a hand during an engineering review can lead to innovations that positively impact our business. Looking for innovation is a continual process and is not limited to a specific Raytheon business or to Raytheon as a whole. Rather, innovation can come from any Raytheon business or from outside Raytheon; reapplying an innovation is again innovative. We should all continue our innovative thinking and look all around us for how to apply other innovations to our businesses. How does Raytheon decide when to invest in internal research versus obtaining the technology externally, and what role do universities play in the technology strategy? Marty R.: Generally, we invest internally in technology that can provide a major competitive discriminator, and we rely on externally available technology (e.g., commercial off the shelf [COTS], etc.) for commodity items. Examples of competitive discriminators are advanced electro-optic/infrared and radio RF sensors, analog and digital electronics, and algorithms. While our electronics use many COTS components, the architecture, packaging design, firmware and software provide the discriminator. Both development and recurring costs are also significant factors, and this constraint also drives the decision. We are starting to place more emphasis on universities as a technology source, mainly with regard to low technology readiness level (TRL) technology that needs to be matured before we seriously consider its use. Across Raytheon, we are involved with and participate in multiple university consortia, including the Defense Advanced Research Projects Agency (DARPA) Semiconductor Technology Advanced Research Network (STARnet), the Arizona State University (ASU) Sensor Signal and Information Processing (SenSIP) Center, the National Science Foundation supported Center for Surveillance Research (CSR), and others. Membership in these groups provides Raytheon the opportunity to obtain and leverage collaborative research results at reasonable membership costs. We also work with individual universities, providing Raytheon opportunities to develop a campus presence, support recruiting and collaborate with professors who are performing research in areas with potential application to our products and customer needs. How does a person get involved in Raytheon research, technology and innovation? John Z.: Research, technology and innovation are core to Raytheon’s business and culture. There are multiple ways to get involved, whether at the front end in generating new ideas or after a contract award in executing successful programs. At the corporate level, we foster early-stage technology identification, maturation, and assessment through our IDEA, RIC and core research programs. Each business also sponsors innovation activities and has processes to identify and support IRAD projects that enable new capabilities. Raytheon also works with our customers to develop technology through CRAD contracts and as part of program upgrades. A good mechanism for engineers and technologists to learn more about Raytheon technology activities is to participate in a Raytheon Technology Interest Group (TIG). TIGs are community-of-interest groups that enable Raytheon engineers and technologists with similar interests to exchange information via meetings, workshops and other activities. The TIGs cover a broad range of technology areas and are open to anyone who wants to attend. • RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 41 on Technology Raytheon Enhances Its Sensor Technology Portfolio With the Acquisition of Poseidon Scientific Instruments Introduction Raytheon is committed to the success of our global radar customers through our technological leadership in radio frequency (RF) sensor systems. Our ability to provide next generation capabilities has increased with the acquisition of Australian technology company Poseidon Scientific Instruments (PSI), developers of the world’s highest-performance microwave signal generators. PSI expands Raytheon’s brand in world-class sensor systems by providing expertise in ultra-low-phase-noise signal generation and companion measurement technologies. These technologies provide new levels of system performance and mission capabilities for the tor technology that is critical to establishing and sustaining oscillation. the mid-1990s of new threats drove even more demanding radar sensitivity requirements that pushed the limits of SAW-based exciters. High-performance, low-phase-noise microwave MO technology evolved over the decades from klystron oscillators in the 1950s, to frequency-multiplied quartz crystal oscillators, to frequency-multiplied surface acoustic wave (SAW) oscillators in the 1990s. This technology evolution has enabled radar systems to achieve higher levels of sensitivity. PSI Technologies Raytheon and the warfighter needed a leapahead technology to achieve the increased radar sensitivity necessary to combat new emerging threats. Enter PSI and their ultra-highperformance sapphire resonator technology. Founded in 1987, PSI is recognized worldwide by international and U.S. defense and commercial industries as a leader in generating and subsequently analyzing ultra-low-phase-noise microwave signals for high sensitivity radar and communications systems. By the early 1990s, PSI’s compact sapphire resonator was a reality. It employed a single synthetic sapphire resonator that offered orders of magnitude reduction in microwave oscillator noise over our SAWbased solutions. From the mid-1990s to 2000, Raytheon and PSI engineers independently developed and demonstrated a sapphire-based MO, built around PSI’s patented sapphire resonator technology. Raytheon’s proof-of-concept MO and related exciter architecture were used to demonstrate a new level of radar performance. At the same time, PSI had fully productized their compact sapphire-based oscillator into a shoebox size Figure 1. High performance sapphire resonator oscillator solutions: the Sapphire Loaded Cavity Oscillator (SLCO) (left) and Shoebox Oscillator® (SBO) (right) — Setting the bar for superior sensor sensitivity. Radar Oscillator Background Radar systems consist of several major subsystems, including a receiver-exciter, transmitter, signal data processor and power system, each of which performs a specific role in radar operation. For the receiver-exciter subsystem, a master oscillator (MO) is used to provide the phase reference for transmit, receive and radar timing functions. It is the spectral purity of the MO, measured as power spectral density and conventionally expressed as amplitude modulation or phase modulation noise, that, in part, establishes the receiver-exciter noise and in turn, the radar’s detection sensitivity. In the presence of large clutter, MO noise can mask small targets and thus limit a radar’s detection sensitivity. Moreover, at the heart of every MO is a narrow-bandwidth, high-stability, resona- 42 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY Furthermore, Raytheon’s novel SAW resonator and oscillator technologies have delivered outstanding radar system performance for several decades. However, the emergence in Phase Noise (dBc/Hz) U.S. warfighter and our international coalition partners. - 80 - 90 - 100 - 110 - 120 - 130 - 140 - 150 - 160 - 170 - 180 0.1 1 10 100 1,000 10,0000 Offset Frequency (kHz) 400 MHz SAW Oscillator at 10.24 GHz 10.24 GHz Sapphire Oscillator Figure 2. Sapphire technology performance comparison: -20 dB better phase noise performance opens new doors for radar performance. Multifunction Radio Frequency Systems integration of these technologies with Raytheon technologies and architectures opens doors to new commercial and defense opportunities, in particular in the area of communications where ultra-high stability (i.e., low phase noise/jitter) clock oscillators are essential. The importance of precision timing continues to increase to support higher speed communications protocols and to support an ever expanding wireless environment that continues to be constrained by fixed operational bandwidth allocations. Figure 3. The Oscillator Development INstrument (ODIN®) phase noise analyzer — Designing and delivering state-of-the-art sources requires a commensurate state-of-the-art noise measurement capability. form factor suitable for radar applications. This new sapphire-based exciter forms the foundation of many of our current, highperformance radar systems and continues to provide Raytheon radar systems with industry leading levels of performance. Searls who, early on, saw the potential and value in transitioning the cryogenic sapphire resonator technology from his gravity wave work at the University of Western Australia (UWA) in Perth, into a product for commercial and defense applications. Raytheon Australia’s PSI Sapphire Loaded Cavity Oscillator (SLCO) and Shoebox Oscillator® (SBO) are shown in Figure 1. The SBO design represents a groundbreaking productized capability for use in tactical defense systems. These microwave oscillators are used today in premier Army, Navy and Air Force sensor systems and are used as laboratory standards at the National Institute of Standards and Technology (NIST) and the U.S. Naval Surface Warfare Center, Crane Division. Figure 2 shows the superior performance of the Raytheon Australia sapphire oscillator. During the development of its sapphire oscillators, PSI needed measurement tools that were not limited by conventional semiconductor performance. To meet this need, PSI developed ODIN® (Oscillator Development INstrument) – a sophisticated phase noise analyzer (Figure 3). ODIN was developed out of necessity to support measurement of their low-noise sapphire sources, but it evolved into a standalone, commercially competitive product line. For less demanding applications, PSI’s dielectric resonator oscillator (DRO) product line provides lower-cost solutions. PSI also has a family of low noise, regenerative frequency dividers that can be used to derive additional, lowerfrequency signals. PSI’s sapphire source and noise degeneration technology has its roots in the field of gravity wave detection, which required a unique, high-performance measurement system offering many dual use and technology transition opportunities into radar and sensor programs. However, it is the innovation and vision of PSI’s founder and managing director Jesse Raytheon-PSI Today PSI technologies are currently being integrated into Raytheon products in the U.S. The In addition to PSI’s resonator technology, their RF engineering design and test skills provide Raytheon Australia with enhanced engineering expertise. Recently, PSI delivered 16 receiver systems for the Murchison Widefield Array (MWA) telescope system. Figure 4 shows portions of this system. The receiver components were designed at different universities and other research organizations worldwide as part of an international scientific consortium that sponsors the MWA telescope project. PSI designed the receiver node enclosure, integrated all of the components into their enclosure, tested each node and delivered them to the MWA team to support system integration and testing. During the PSI and Raytheon integration process, opportunities to grow and expand PSI’s footprint in commercial and international markets for low-noise products will continue to be explored as well as opportunities to enhance current and future Raytheon products with PSI technologies. • Robert E. Desrochers II, Mark Koehnke and Jesse Searls Images courtesy of the Murchison Widefield Array via Curtin University Figure 4. Murchison Widefield Array equipment: 4 x 4 antenna tile (left) and Raytheon Australia PSI integrated receiver node (right). Each receiver node supports eight tiles for a total of 128 dual-linear-polarization antenna elements. RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 43 SPECIAL INTEREST Raytheon’s Collaboration With Worcester Polytechnic Institute Raytheon recruits engineers from more than 70 universities around the world. In addition to recruitment, Raytheon collaborates with universities in engineering research, training and sponsorship of science, technology, engineering and mathematics (STEM) activities. This article highlights the collaboration between Raytheon and Worcester Polytechnic Institute (WPI) in these areas. STEM Sponsored Initiatives Raytheon and WPI are committed to STEM education and in fostering and maintaining excitement among students in STEM disciplines. WPI’s STEM Education Center provides training for K-12 educators and administrators, and Raytheon supports several of WPI’s STEMrelated programs, such as RoboNautica, a major FIRST Robotics event that showcases the talented young minds of tomorrow’s engineers and scientists, Camp Reach, a summer camp for seventh grade girls that introduces the principles of engineering via hands-on experiences, and TouchTomorrow, a free interactive festival with exhibits and activities focused on the future of science and technology. These programs support Raytheon’s objective of encouraging students’ enthusiasm 44 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY for engineering and practical applications of theoretical concepts, ultimately, to enable them to become future technology leaders. Raytheon is proud to support these great events and WPI’s commitment to educating our future scientists and engineers, as well as the educators and administrators in our primary and secondary schools. Program Protection Planning Program Protection Planning (PPP) is a disciplined process that helps ensure adequate protection of a program’s technology, components, and information from unauthorized collection, exploitation or use. WPI has been designated as a center of excellence in cybersecurity research by the National Security Agency and the Department of Homeland Security, leading the way in PPP training by launching the first graduate program aligned with the new Department of Defense (DoD) policies. As part of that program, WPI developed a PPP certificate program based on the systems security engineering needs requested by Raytheon and others in the industry. The WPI PPP program, launched in 2013, continues to help expand Raytheon’s workforce proficiency in systems security engineering. Raytheon plans on leveraging the WPI program to educate our workforce in PPP implementation as we develop holistic approaches to vulnerability assessment and secure designs that integrate across anti-tamper, information assurance (cyber security), software assurance and supply chain risk management. WPI’s PPP program complements Raytheon’s in-house intensive training for cyber experts and its awareness training for all employees by providing an additional training option for those who want to learn more about PPP but are not enrolled in the cyber expert training. The program is accredited and can be used as part of a master’s degree program. Technology Development and Sponsorship Raytheon is partnering with WPI for research in digital computing design and architecting. WPI’s strength in this area is evident in its recent success in the Defense Advanced Research Projects Agency (DARPA) robotics challenge and ongoing research in processing intensive applications, such as communications and radar. Raytheon collaborated with WPI in applying field programmable gate arrays (FPGAs) to software defined radios (SDR). Traditionally, applying FPGAs to engineering problems has presented challenges due to the specialized knowledge required by the designer. As part of the Raytheon-sponsored WPI research, model-based development tools and techniques were investigated to help ameliorate these challenges, specifically for the development of FPGA-based SDR solutions. The tool set developed for this research utilized different modulation and demodulation models that were simulated and analyzed using the MathWorks Simulink® and MATLAB® tools. The resulting designs were translated into very high-speed integrated circuit hardware SPECIAL INTEREST description language (VHDL) software using the MathWorks HDL Coder™, and then implemented on a Xilinx Zynq™ 7000 All Programmable System on a Chip (SoC) (Figure 1). Raytheon and WPI are also collaborating in other research areas such as distributed beam forming, where algorithms are being developed to control the transmission of a common message by multiple distributed antennas with the goal of maximizing the signal strength at the receiving location (Figure 2). WPI professors contributed to Raytheon research on the modeling and management of co-located radio frequency emitters (RF) such as the ones that exist on the Navy’s Zumwaltclass ships, and in the real-time processing of three-dimensional radar images using general purpose graphics processing units (GP-GPUs). Raytheon also sponsored WPI research on improving the performance of satellite and terrestrial communication links. ZedBoardTM supplied by Avnet, Inc. Figure 1. The test hardware for the software defined radio (SDR) implementation utilizes a Xilinx Zynq™ 7000 All Programmable System on a Chip (SoC). Figure 2. Algorithms are being developed to control the transmission of a message from multiple distributed antennas to optimize the performance of wireless communication systems. across the world to take advantage of their unique capabilities and leading edge research, and to provide stimulating and important learning opportunities for future engineers and technologists. These partnerships also help Raytheon identify new technologies and potential employees to help enhance our leadership position in defense and aerospace systems through world-class people, innovation and technology. • Stephen Freitag, James McGrath and Elizabeth Wilson, Ph.D. These technical collaborations enable research in important areas and offer WPI students and professors the opportunity to solve challenging real-world problems. Raytheon Careers WPI graduates follow rigorous curricula with multiple project completion requirements. Their problem-solving skills, developed through theory and practice, prepare them to help solve challenging engineering and technological problems, such as those found at Raytheon. Many Raytheon employees are WPI alumni. Among them are significant contributors nationwide. Some have risen to leadership and senior leadership ranks; some are subject matter experts and are well-respected for their knowledge and leadership. Among the WPI alumni are product line vice presidents, engineering vice presidents and our Chief Technology Officer. The WPI PPP program complements Raytheon’s in-house intensive training for cyber experts and its awareness training for all employees by providing an additional training option for those who want to learn more about PPP but are not enrolled in the cyber expert training. The Raytheon-WPI relationship is an example of how Raytheon is partnering with universities RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 45 SPECIAL INTEREST Raytheon’s Partnership With the Franklin W. Olin College of Engineering Gives Students Real-world, Project-based Experience Raytheon has a legacy of supporting science, technology, engineering and mathematics (STEM) programs to foster the creation of the next generation of university graduates and researchers. Programs such as MathMovesU® look to engage middle school students in math and science by showing them how these disciplines connect to everyday life. Raytheon actively supports programs like FIRST® (For Inspiration and Recognition of Science and Technology) Robotics and the Team America Rocketry Challenge (TARC) to expand STEM initiatives beyond middle school. Additionally, Raytheon actively supports research and development (R&D) activities through university-directed research projects and contract R&D programs. One such unique partnership that Raytheon has supported for the past five years with the Franklin W. Olin College of Engineering is the Senior Capstone Program in Engineering (SCOPE). Olin College — which opened in 2002 in Needham, Mass. — seeks to redefine undergraduate engineering education by emphasizing a project-based curriculum to prepare students to become engineering innovators who address broad societal needs. From their first semester at the college, students take classes that involve hands-on projects. In SCOPE, which is the culmination of this project-based curriculum, teams of students work for an academic year with a corporate partner on a real-world engineering project that the sponsor values. The program has been very successful in preparing students to function in the real-world industry environment when they become practicing engineers upon graduation. The SCOPE team. From left: Sasha Sproch, Anton Frolenkov, Vidie Pong, Terry Kirn, Amy Whitcombe and Rob Leoni. 1 Olin College’s collaboration with Raytheon in particular gives students experience working on industry research-oriented projects. While many SCOPE projects involve research and development, the Raytheon projects — some of which are described below — are unique in that they are much more research than development oriented. Students who are considering a research-oriented career in academia or industry gain valuable insight into how research is executed within a major defense company. Additionally, the Raytheon projects have required students to use some of the more abstract material covered in Olin College’s curriculum (particularly signal processing), providing students experience applying abstract theory to real-world engineering problems. Raytheon recently began its sixth year supporting the Olin College SCOPE program, and it has helped students explore some exciting research topics throughout its history. For example, Raytheon collaborated with Woods Hole Oceanographic Institution to create a SCOPE research project on the energy management of buoys that can be deployed in remote locations as part of the Ocean Observatories Initiative1 (OOI). The project team explored the use of various energyharvesting systems and used this knowledge to establish a power management simulator for the remote buoy system. Another Raytheon SCOPE team looked at the feasibility of using communications waveforms to connect a set of networked X-band radars and explored what a deployment scenario might look like to realize this capability. A follow-on SCOPE team took this feasibility study and demonstrated X-band communications waveforms The Ocean Observatories Initiative (OOI) is a National Science Foundation funded (NSF-funded) program to establish a networked sensor system to monitor the ocean and seafloor. 46 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY SPECIAL INTEREST Data Communications Waveform Signal to Transmit Radar Non-Linear Amplifier Transmitted Signals Active Electronically Steered Antenna Radar Waveform Figure 1. Graphic of communication and radar waveforms transmitted through a single power amplifier. between separate sites in collaboration with the National Science Foundation’s Collaborative Adaptive Sensing of the Atmosphere (CASA) program, which is being led by the University of Massachusetts at Amherst. The past three Raytheon SCOPE teams (2011–2013) have focused on investigating ways of mitigating the negative effects of sending multiple signals simultaneously through a single radio frequency (RF) transmitter. This is a vibrant area of research for both civilian and defense systems as the development of successful mitigation methods could lead to significantly reduced system cost and footprint because one system would be capable of performing many simultaneous functions that today require multiple systems. In mobile telecommunication systems, these mitigation techniques will enable more efficient Figure 2. SCOPE lab set-up for the current Raytheon project. The team uses a sophisticated set of test equipment to monitor and analyze the performance of their multiwaveform tests. use of valuable, limited spectrum resources as ever higher bandwidth data connections are required such as those called for in the long-term evolution (LTE) advanced standard that requires bandwidths up to 100 MHz. The defense community has also been pursuing this research in order to enable the transition to integrated multifunction, multibeam radio frequency (RF) arrays, which will reduce the number of systems and associated antennas required for each individual function. These new multifunction RF systems must be capable of simultaneously supporting communications and radar missions. While radar transmitters require extremely high RF power, communication systems are focused on signal integrity and spectral purity with adequate RF power. Today’s multifunction transmitter design approaches require significant compromises in the RF power, prime power, thermal management and spectral purity in order to perform both missions. The final stage of RF amplification in the transmitter part of these systems determines, to a large extent, the capabilities of the overall system and therefore the SCOPE teams have been focusing on understanding the relationship between the amplifier and signal interplay to develop improved design approaches through the use of new classes of waveforms (Figure 1). Throughout the projects, the Raytheon SCOPE teams have evaluated existing multifunction system designs as well as new designs by developing and validating a unified simulation and experimental test bench (Figure 2) that is applicable to Raytheon’s unique and specific needs. The 2010–2011 team focused on developing the basic simulation infrastructure using an industry standard tool, Agilent’s Advanced Design System. The team used a generic, somewhat idealized, model for the power amplifier in order to focus their effort on the signal-side of the problem. A high-fidelity model for the amplifier and an experimental test bench for verification and validation of the simulated performance were developed by the 2011–2012 team. The current SCOPE team developed example pairs of radar and communication waveforms, which were exercised both in the simulator and on the test bench. Through the cumulative efforts of all three teams, they have identified, simulated, and tested advanced signal construction concepts that may lead to improved multifunction transmitter performance. They also identified future areas of research that can further advance the state-of-the-art. The partnership between Raytheon and Olin College pairs two advocates of the engineering design process and demonstrates a model of project-based learning that can be used to engage the next generation of research engineers to help create future technologies. While the SCOPE collaboration has yielded positive and fruitful research, it is the development of the next generation of engineering innovators that likely yields the most important benefits. By providing real-world interesting experience to these college engineers, they are being encouraged to pursue careers in STEM after graduation, thus helping to ensure a technically strong workforce for the future. Quoting Anton Frolenkov (2012–2013 SCOPE team member) who is currently pursuing a master’s degree in electrical engineering at the University of Michigan, Ann Arbor, “I really appreciated the lessons I learned and have since been able to apply. As with anything, the amount of reward is directly proportional to the amount of effort exerted. I felt like I worked hard to push the project along and as such learned a lot about debugging and research project management along with obvious technical lessons. I also enjoyed the collaboration aspect of SCOPE. On many levels, I wish it were possible to devote as much time to the project as a full-time internship affords.” • Terry Kirn RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 47 M United States Patents Issued to Raytheon MARK W. BIGGS, TIMOTHY R. SCHEMPP, GREGORY S. UM 8344946 Single frequency user ionosphere system and techinique MIKEL J. WHITE 8362849 Broadband balun RICHARD A. POISEL 8345597 Systems and methods for detecting spread spectrum signals in an area of interest HEE KYUNG KIM, CLIFTON QUAN, ALBERTO F. VISCARRA, FANGCHOU YANG 8362856 RF transition with three-dimensional molded RF structure MATTHEW L. SHAW, MATTHEW G. WOODARD At Raytheon, we encourage people to work on technological challenges that keep America strong and develop innovative commercial products. Part of that process is identifying and protecting our intellectual property (IP). Once again, the U.S. Patent Office has recognized our engineers and technologists for their contributions in their fields of interest. We congratulate our inventors who were awarded patents from January through June 2013. DONALD PRICE, GARY SCHWARTZ, WILLIAM G. WYATT 8341965 Method and system for cooling MICHAEL BRENNAN, EDWARD DEZELICK, LUIS GIRALDO, BRETT GOLDSTEIN, MICHAEL MILLSPAUGH, JOHN RYAN, ROBERT WALLACE 8342069 Device and method for controlled breaching of reinforced concrete ROBERT D. TRAVIS 8342070 Methods and apparatus for a control surface restraint and release system SCOTT H. ALLEN, JONATHAN T. LONGLEY, JAMES H. ROONEY III 8342281 Hull robot steering system TERRY M. SANDERSON, DAVID R. SAR 8342457 Shape-changing structure member with embedded spring TIMOTHY A. MURPHY, TIMOTHY R. WERCH 8342867 Free floating connector engagement and retention system and method for establishing a temporary electrical connection MATTHEW R. DEXTER, MARION P. HENSLEY 8345639 Broad propagation pattern antenna BLAISE ROBITAILLE 8346035 Two stage integrator assembly DOUGLAS BROWN, GEOFF HARRIS, DANIEL MITCHELL 8347814 Method and apparatus for coating a curved surface THOMAS W. BASTIAN 8350201 Systems, apparatus and methods to compensate for roll orientation variations in missile components NATHAN M. MINTZ, KALIN SPARIOSU 8350223 Quantum dot based radiation source and radiometric calibrator using the same MARY K. HERNDON, MATTHEW A. MORTON, PAYAM SHOGHI 8350777 Metamaterial radome/isolator MARK A. GLOUDEMANS, DAVID E. MUSSMANN, THOMAS E. YOUNG 8351534 Distributed maximal ratio combining receiver architecture IVANS S. CHOU, CLARA CURIEL, LAWRENCE C. DE PAULA, FREDERICK C. MERTZ, ROBERT K. PINA, KARLEEN G. SEYBOLD 8351770 Imaging station and method for repeatable alignment of images CINDY W. MA, DEREK PRUDEN, KEVIN C. ROLSTON, ALBERTO F. VISCARRA 8354595 Adhesive reinforced open hole interconnect ROBERT W. MARTIN 8354627 Torsion stop deployment system for airborne object PREMJEET CHAHAL, FRANCIS J. MORRIS 8343806 Hermetic packaging of integrated circuit components RAYMOND D. EPPICH 8354833 Method for characterizing dielectric loss tangent JESSE H. BLAKE, CARLOS E. GARCIA, MATTHEW G. MURPHY 8344302 Optically-coupled communication interface for a laserguided projectile JACOB KIM, GILBERT M. SHOWS 8354958 Alignment system CHRIS E. GESWENDER 8344304 Methods and apparatus for missile air inlet JOHN P. BETTENCOURT, NICHOLAS J. KOLIAS 8344359 Integrated thermoelectric heat pump to cool GaN transistors PREMJEET CHAHAL 8344430 Multiple substrate electrical circuit device JASON M. BAIN, CHARLES M. DE LAIR, RUDY A. EISENTRAUT, MATTHEW A. OFFOLTER 8344525 Electrical power initiator system and method PETER R. DRAKE, YUCHOI F. LOK 8344937 Methods and apparatus for integration of distributed sensors and airport surveillance radar to mitigate blind spots MARK ACKERMAN, SCOTT R. CHEYNE, JEFFREY PAQUETTE 8355255 Cooling of coplanar active circuits NATHAN M. MINTZ, MARK R. SKIDMORE 8356775 Space object deployment system and method EDDIE R. BROCK 8358240 Generating a time deterministic, spectrally noncoherent signal STEPHEN JACOBSEN, DAVID MARCEAU, FRASER M. SMITH 8358462 A mini-scope for multi-directional imaging THOMAS FARLEY, TINA A. OBERAI, JERRY L. PIPPINS JR., RICARDO J. RODRIGUEZ, NOAH Z. STAHL, DANIEL TEIJIDO, JAY J. VISARIA 8359357 Secure e-mail messaging system ANTHONY J. DELROCCO, DANIEL TEIJIDO 8359641 Multi-level secure information retrieval system CHI-YUNG CHANG, MICHAEL Y. JIN 8344942 System and method for resolving ambiguity in radar, lidar, and acoustic systems JAIME ROBLEDO 8360396 Leverage tool for a crank assembly of a radar system VERNON R. GOODMAN 8344944 Method and system for continuous wave interference suppression in pulsed signal processing WILLIAM B. KING, CHAUNCHY F. MCKEARN 8362410 Source-independent beam director and control system for a high-energy electromagnetic radiation source 48 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY TIEN M. NGUYEN, JOHN J. WOOTAN 8362945 Systems and methods for detecting and tracking gun barrels using millimeter waves PETER ROZITIS, KEVIN WAGNER 8363317 Flourescence microscopy focus drive SCOTT R. CHEYNE, JOSEPH R. ELLSWORTH, JEFFREY PAQUETTE 8363413 An assembly to provide thermal cooling GREGORY V. BURNETT, MICHAEL K. HOLZ, NATHAN M. MINTZ, BRANDON W. PILLANS, ANTHONY ROSS 8364439 System and method for detection of concealed cargo in a vehicle by center of mass measurement RALPH H. KLESTADT, JAVIER VELEZ 8367993 Aerodynamic flight termination system and method SCOTT T. JOHNSON, SHADI S. MERHI 8368208 Semiconductor cooling apparatus FRANCIS J. MORRIS, BRANDON W. PILLANS, MIKEL J. WHITE 8368491 Systems and methods for providing high-capacitance RF MEMS switches MARTT HARDING, MICHAEL D. PIXLEY 8368559 Network of traffic behavior-monitoring unattended ground sensors DAVID R. BISHOP, JERRY M. GRIMM, JAMES F. KVIATKOFSKY, GARY F. WAHLQUIST, KUANG-YUH WU 8368610 Shaped ballistic radome KENN S. BATES 8368760 System and method for dynamic infrared targeting DELMER D. FISHER, BRADY A. PLUMMER, ROBERT W. PLUMMER 8369062 Detonation control system MARION P. HENSLEY 8369445 A system and method for improved communication utilizing velocity related information ALEKSEY NOGIN, DAVID PAYTON 8370422 Establishing common interest negotiation links between consumers and suppliers to facilitate solving a resource allocation problem JAIME ROBLEDO 8371006 Rotary mechanical vibration mechanism JAMES H. DUPONT, STEVEN J. ELDER 8371204 Bubble weapon system and methods for inhibiting movement and disrupting operations of vessels JAMES F. ASBROCK, BRYAN W. KEAN, KANON LIU 8373458 Read out integrated circuit KENT P. PFLIBSEN, DARIN S. WILLIAMS 8374404 Iris recognition using hyper-spectral signatures ERIC P. LAM, CHRISTOPHER A. LEDDY, STEPHEN R. NASH, HARRISON A. PARKS 8374453 Integrating image frames MATTHEW L. SHAW, MATTHEW G. WOODARD 8375045 Translating a binary data stream using binary markup language (BML) schema JOHN R. STALEY 8375620 Weapon sight having multi-munitions ballistics computer ERIK T. DALE, RYAN A. EGBERT 8375861 Projectile that includes a gimbal stop GEORGE L. FIX, JAMES R. STURGES, ROBERT E. WALSH 8378212 Sealed electrical feed-through assembly and methods of making the same JOHN M. BRANNING JR., ROBERT A. LEMIRE 8378881 Systems and methods for collision avoidance in unmanned aerial vehicles WILLIAM P. HAROKOPUS 8378893 Patch antenna JAR J. LEE, STAN W. LIVINGSTON, CLIFTON QUAN 8378905 Airship mounted array MARK S. HAUHE, CLIFTON QUAN, ROHN SAUER 8378916 Systems and methods for providing a reconfigurable groundplane PAUL A. MEREMS 8387540 Interceptor projectile and method of use TIMOTHY D. SMITH 8387914 Solar thermal rotorcraft STEFAN T. BAUR, ADAM M. KENNEDY, DAVID R. RHIGER 8389947 Method and system for detecting neutron radiation MATTHEW S. NOELL 8390269 Non-destructive determination of functionality of an unknown semiconductor device JAMES CARROLL, JOHN G. HESTON, JOHN R. STANTON 8390395 High power RF switch with active device size tapering RICHARD A. GILSTRAP, CHUL J. LEE 8390508 Generating radar cross-section signatures JAR J. LEE, STAN W. LIVINGSTON, JEFFREY B. WEBER, FANGCHOU YANG 8390520 Dual-patch antenna and array CASEY T. STREUBER 8390801 Angle measurement for a wide field-of-view (WFOV) semi-active laser (SAL) seeker GARY A. FRAZIER 8379293 Method and apparatus for modulating light DOUGLAS M. ZOUCHA 8391549 Methods and systems for processing data using product-law symmetry detection DONALD DENIS, CATHERINE GREENHALGH, STAN SZAPIEL 8379321 Extended depth of field imaging PAUL H. GROBERT, WILLIAM K. WALLACE 8391772 GPS aided open loop coherent focusing YVONNE C. LEVENSON, TERRY M. SANDERSON, DAVID R. SAR 8382042 Structure with reconfigurable polymer material STEPHEN JACOBSEN, MARC OLIVIER 8392036 Point and go navigation system and method MICHAEL CRIST, DONALD P. GRAHAM, MARY HEWITT, HECTOR M. REYES JR. 8384540 Systems and methods for detecting and geo-locating hazardous refuse CHARLES T. HANSEN 8384588 Beam stabilization for wideband phase comparison monopulse angle estimation with electronically steered antennas GORDON R. SCOTT 8384609 RF aperture coldplate STEPHEN JACOBSEN, JAMES H. ROONEY III, FRASER M. SMITH 8386112 Vessel hull robot navigation subsystem MICHAEL R. JOHNSON, BRUCE E. PEOPLES, JONATHON P. SMITH 8386489 Applying formal concept analysis to validate expanded concept types MARK A. GLOUDEMANS 8386902 Low-complexity method for rational puncturing of forward error correcting codes ROBERT CAVALLERI, LLOYD KINSEY JR. 8387360 Integral thrust vector and roll control system GARRETT L. HALL, MICHAEL R. JOHNSON 8387507 Weapon interceptor projectile with deployable frame and net TIMOTHY J. IMHOLT 8387534 Detonation device comprising nanocomposite explosive material TERRY M. SANDERSON, DAVID R. SAR, PHILIP C. THERIAULT 8387536 Interceptor vehicle with extendible arm STEVEN J. ELDER 8387538 Projectile having casing that includes multiple flachettes MICHAEL K. BURKLAND, CASEY T. STREUBER, KRISTOFER E. TVEDT 8392143 Fixed-source array test station for calibration of a semi-active laser (SAL) seeker BRIAN RICHARD BOULE, JONATHAN T. LONGLEY, JAMES H. ROONEY III 8393286 Hull robot garage JOEL N. HARRIS, JEREMY C. HERMANN, HOWARD R. KORNSTEIN, JONATHAN T. LONGLEY, JAMES H. ROONEY III, WEN-TE WU 8393421 Hull robot drive system RALPH PENSEL 8393422 Serpentine robotic crawler E. RUSS ALTHOF, SCOTT A. MUSE, WALTER S. POPE, WAYNE K. WOODALL 8398347 Integrated nutplate and clip for a floating fastener and method of manufacture and assembly DOUGLAS BROWN, MARK HANDEREK, GEOFF HARRIS, ANTHONY LIGHT, DANIEL MITCHELL 8398776 Method and apparatus for supporting workpieces in a coating apparatus KENN S. BATES, GENE P. COCHRAN 8399872 System and method for using an optical isolator in laser testing DONALD DENIS 8400712 Methods and apparatus for providing a split field of view in an optical sight THOMAS B. PEDERSON 8400875 Active sonar system and active sonar method using a pulse sorting transform THOMAS BIDIGARE, DANIEL CHANG 8401466 Scalable high speed MIMO-satellite communication system NICHOLAS W. BARRETT, CHRISTOPHER MARKLEY, JOSHUA T. PYLE 8402030 Textual document analysis using word cloud comparison MICHAEL R. JOHNSON, BRUCE E. PEOPLES, BRIAN J. SIMPSON 8402046 Conceptual reverse query expander JAMES H. DUPONT, JEFFREY H. KOESSLER 8402895 Vortice amplified diffuser for buoyancy dissipater and method for selectable diffusion JAMES H. BOSTICK 8403106 Man-portable non-lethal pressure shield THOMAS A. OLDEN 8403267 Ejection system and a method for ejecting a payload from a payload delivery vehicle GEORGE F. BARSON, WILLIAM P. HULL JR., JAMES IRION II, JAMES S. WILSON 8405548 Multi-orientation phased antenna array and associated method RICHARD GOOCH, ALAN ROSCOW 8405550 Near-vertical direction finding and geolocation system BUU DIEP 8393526 System and method for packaging electronic devices GENTIAN JAKLLARI, JASON REDI, CESAR A. SANTIVANEZ 8406175 Carrier sense multiple access (CSMA) protocol with multi-packet reception (MPR) in a wireless ad hoc network MATTHEW JONAS 8393849 Method and system for adjusting a position of an object MONTY D. MCDOUGAL 8407324 Dynamic modification of the address of a proxy ANU AGARWAL, JUEJUN HU, FRANK B. JAWORSKI 8394329 Optical device for detection of agent MARK W. REDEKOPP 8407639 Systems and methods for mapping state elements of digital circuits for equivalence verification MICHAEL D. AMBROSE, BRETT A. ANDERSON, JAMES ROBERT BETZ, EDWARD G. ROBINSON, BRYAN J. WALLACE 8395393 Cable test method ERIC HUANG, DAVID L. II, DEEPAK KHOSLA 8396730 System and method for resource allocation and management BRYAN D. GLICK, DONALD R. KRETZ, RODERIC W. PAULK 8396877 Method and apparatus for generating a fused view of one or more people DOUGLAS BROWN, GEOFF HARRIS, ALEXANDRE LIFCHITS, DANIEL MITCHELL 8398251 Method and apparatus for fabricating a precision optical surface JAMES BARGER 8408115 Systems and methods for an indicator for a weapon sight STEVIE ALEJANDRO, CHRIS E. GESWENDER, PAUL VESTY 8410412 Guidance control for spinning or rolling vehicle LACY G. COOK, JOHN F. SILNY 8411268 Two material achromatic prism RYAN A. EGBERT, CHRISTOPHER L. HERNANDEZ 8411362 Optical element retaining system for sensor systems GREGORY E. LONGERICH, DAVID C. ROBILLARD 8412482 Multi-channel electronic acceleration switch RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 49 BRYAN J. WALASCHEK 8412745 Relational database model optimized for the use and maintenance of watchlist data in a high demand environment DELMAR L. BARKER, JOHN WARREN BECK, WILLIAM RICHARD OWENS 8425735 Fabrication of pillared graphene JAMES BARGER, SCOTT RITTER 8437223 Systems and methods for detecting shooter location from an aircraft SUZANNE P. HASSELL, STEPHEN P. MARRA, KRISTINA L. STEWART, JASON M. SURPRISE 8413115 Specifying integration points of a system-of-systems CHRIS E. GESWENDER 8426788 Guidance control for spinning or rolling projectile ERWIN W. BATHRICK, SUNG I. PARK, DENH T. SY 8437250 Determining paths that satisfy a reliability requirement WILLIAM P. HULL JR., ROBERT E. LEONI, JAMES S. WILSON 8427238 Performance optimization of power amplifier SAMUEL S. BLACKMAN, BRIAN A. CRONIN, NICHOLAS J. PLOPLYS 8437972 Sensor bias estimation for multiple hypothesis tracker JOEL E. LAMENDOLA, STANLEY J. POREDA, MAXIM RAYKIN 8427363 Determining whether a track is a live track or a virtual track DAVID M. DORIA 8438128 Empirical modeling of confusion matrices JOSHUA EDMISON, JOHN-FRANCIS MERGEN 8413154 Energy-aware computing environment scheduler PAUL B. HAFELI, ELI HOLZMAN, AARON J. STEIN, MICHAEL VARGAS 8413320 Method of gold removal from electronic components ROGER W. GRAHAM 8415623 Processing detector array signals using stacked readout integrated circuits MOUNGI BAWENDI, SCOTT GEYER, FRANK B. JAWORSKI 8415759 Down-converting and detecting photons SCOTT E. ADCOOK, CARL D. COOK 8416071 Relative location determination of mobile sensor nodes SALVATORE BELLOFIORE, DAVID J. KNAPP, ALPHONSO A. SAMUEL, GLAFKOS K. STRATIS 8416127 Dynamic calibration radar system LACY G. COOK 8416407 Optical spectrometer with wide field of view fore-optics DARIN S. WILLIAMS 8416986 Methods and systems for processing data using nonlinear slope compensation FREDERICK B. KOEHLER, WARD D. LYMAN 8418455 Shape memory alloy separating apparatuses RICHARD M. LLOYD 8418623 Multi-point time spacing kinetic energy rod warhead and system ERIC C. FEST, JIM R. HICKS, JAMES P. MILLS, NICHOLAS D. TRAIL 8421003 Optical transceiver built-in test (BIT) JOSEPH F. BORCHARD, WILLIAM H. WELLMAN 8422005 Method and apparatus for multiple field-angle optical alignment testing LACY G. COOK, JOHN F. SILNY 8422011 Two material achromatic prism RAFAEL A. IHLY, SHAH A. NEJAD, CHAD WANGSVICK 8422951 Wireless communication system and method for wireless signal communication in flight vehicles DAVID FUCIARELLI, DAVID L. II, JAMES R. ZUBER 8423224 Methods and apparatus for controlling deployment of systems ANDREW B. FACCIANO, ROBERT D. TRAVIS, DALE O. WIDMER, SANDIE S. WORLEY 8424438 Multi-stage rocket, deployable raceway harness assembly and methods for controlling stages thereof ROBERT A. BAILEY 8424439 Systems and methods for launching munitions ALF L. CARROLL III, ERNEST C. FACCINI, LUCINE KABAKIAN REINBOLD, NATHANIEL J. WARD 8424442 Tile grid substructure for pultruded ballistic screens MICHAEL R. JOHNSON, BRIAN J. LUKOW 8424444 Countermeasure systems including pyrotechnicallygimbaled targeting units and methods for equipping vehicles with the same 50 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY JEROME H. POZGAY 8427370 Methods and apparatus for multiple beam aperture JEROME H. POZGAY 8427371 RF feed network for modular active aperture electronically steered arrays DAVID D. CROUCH 8427382 Power combiner/divider for coupling n-coaxial inputs/ outputs to a waveguide via a matching plate to provide minimized reflection LACY G. COOK 8427744 All-reflective relayed focal telescope derived from the first two mirrors of an afocal three-mirror anastigmat ROBERT D. STULTZ 8427769 Multi-stage Lyot filter and method ROBERT C. EARL, GEORGE M. HUME JR. 8428204 Recovering distorted digital data DOUGLAS W. COX, PHILIP J. MILLIS 8428992 Estimating training development hours BRADLEY M. BIGGS, TIM B. BONBRAKE, GEORGE D. BUDY 8430028 Shock dampened explosive initiator assembly and method for dampening shock within a delivery vehicle PHILIP C. THERIAULT 8430578 Separation of main and secondary inertial measurements for improved line of sight error of an imaging vehicle’s isolated detector assembly JAMES GABURA 8432433 Method and apparatus for colorizing a monochrome infrared image CHRISTOPHER FLETCHER, FRANK B. JAWORSKI 8432467 Integrated detection and display imaging system and method BRIEN ROSS, STAN SZAPIEL 8432610 Multi-magnification viewing and aiming scope JONATHAN HABIF 8433070 Systems and methods for stabilization of interferometers for quantum key distribution STEPHEN JACOBSEN, DAVID MARCEAU 8434208 Method for manufacturing a complex structure THOMAS R. BERGER, SAMI DAOUD, MICHAEL J. VILLEBURN 8434411 Cluster explosively-formed penetrator warheads JOHN CORRADINI 8436285 Projectile that includes a fin adjustment mechanism with changing backlash LACY G. COOK, IAN S. ROBINSON, YIFAL J. SHAHAM 8436992 Low distortion spectrometer JERRY HINSON 8438201 Digital fractional integrator ROBERT HARROVER, JOHN S. LEAR, JOHN E. STEM, KENNETH W. WRIGHT, JULIAN A. ZOTTL 8438296 Playback communications using a unified communications protocol WALTER C. MILLIKEN 8438401 Device and method for securely storing data KENT P. PFLIBSEN, CASEY T. STREUBER 8440972 Radiation detector with microstructured silicon EDWARD P. SMITH 8441087 Direct readout focal plane array MIKEL J. WHITE 8441322 Broadband linearization by elimination of harmonics and intermodulation in amplifiers EMMANUEL NEGATU, THEODORE VORNBROCK, JOHN GEORGE WITZEL 8441360 Search and rescue using ultraviolet radiation MICHAEL G. ADLERSTEIN 8441385 Power digital to analog converter THOMAS R. BERGER, SAMI DAOUD, MICHAEL J. VILLEBURN 8444784 Insensitive munition-type BNCP explosive material and methods for forming the same WAYNE L. SUNNE 8445822 One-piece nano/nano class nanocomposite optical ceramic (NNOC) extended dome having seamless non-complementary geometries for electro-optic sensors DARIN S. WILLIAMS, RICHARD J. WRIGHT 8445823 Guided munition systems including combustive dome covers and methods for equipping guided munitions with the same VICTOR D. KRUPPA, RICHARD A. SCHMIDT 8445836 System for maintaining an even temperature distribution across a laser detector ANDREW M. PIPER, MATTHEW D. THOREN 8445864 Method and apparatus for anti-biofouling of a protected surface in liquid environments TERRY C. CISCO, MARY A. TESHIBA 8446230 Microwave directional coupler CHARLES A. CORWIN, DAVID C. FISHER, SARAH E. LAW 8446310 Method and system for locating signal jammers MICHAEL K. BURKLAND 8447550 Compact fixed-source array test station for calibration of a semi-active laser (SAL) seeker JOE H. LINDLEY, GARY THOMAS 8448127 Software forecasting system RICHARD GUERRERO, NICHOLAS L. SELLIER 8448246 Protecting sensitive email ALF L. CARROLL III, DONALD L. CHALOUPKA, KATHERINE E. HOFFMAN, NATHANIEL J. WARD 8448561 Weapon mount MAREK GAJEWSKI 8456134 System and method for applying a plurality of energy pulses to a cathode for rapid depolarization of batteries BRIAN M. WHITE, COLIN WHITE 8448718 Modified hand-held tool THOMAS E. WOOD 8456350 Methods and apparatus for sea-state measurement via radar sea-clutter eccentricity JAYSON KAHLE BOPP, JAMES A. NEGRO 8449009 Adapter for attachment of a display unit to a console of a vehicle MARY K. HERNDON, RALPH KORENSTEIN, CHAE DEOK LEE 8450185 Semiconductor strutures having directly bonded heat sinks and methods for making such structures LARRY A. BOOKER, JOHN W. GERSTENBERG 8450951 System and method for gyrotron power regulation THOMAS E. WOOD 8456352 Methods and apparatus for automatic STC from sea-state measurement via radar sea-clutter eccentricity DOUGLAS BROWN, GEOFF HARRIS, DANIEL MITCHELL 8456740 Method and apparatus for pathlength adjustment in an optical system CHARLES S. KUEHL, WILLIAM T. STIFFLER 8457034 Airborne communication network MICHAEL L. FORSMAN, JAMES J. MAYS, MICHAEL L. WILLIAMS 8468246 System and method for allocating resources in a distributed computing system RANDALL S. BROOKS, DANIEL TEIJIDO 8468344 Enabling multi-level security in a single-level security computing system BRADLEY T. FORD, RANDY S. JENNINGS, KEVEN K. KALKBRENNER, MONTY D. MCDOUGAL, BRIAN N. SMITH, WILLIAM E. STERNS 8468602 System and method for host-level malware detection TIMOTHY E. ADAMS, CHRISTOPHER MOSHENROSE, JAMES A. PRUETT 8469330 Systems and methods for securing objects to vehicles GARY A. FRAZIER, CODY B. MOODY, BRANDON W. PILLANS 8451070 Self-powered microelectromechanical oscillator DMITRI JERDEV 8457418 Local area contract enhancement ROBERT R. CLARKSON 8471567 Circuit for detection of failed solder-joints on array packages BENJAMIN J. ANNINO, ROGER L. CLARK, WILLIAM W. COOPER, MARK J. GUGLIUZZA 8451071 Low noise oscillators JOHN J. COOGAN, KEVIN PETERSON 8457437 System and method for enhancing registered images using edge overlays KENNETH A. ESSENWANGER 8471646 Wideband, differential signal balun for rejecting common mode electromagnetic fields STEVEN T. CUMMINGS, JOSEPH LICCIARDELLO, PETER D. MORICO, STEPHEN J. PEREIRA, JEROME H. POZGAY, ANGELO M. PUZELLA, JAMES A. ROCHE JR., MICHAEL G. SARCIONE 8451165 Mobile radar system JOHN GRIFFITH III, JOHN-FRANCIS MERGEN, CARL POWELL 8458491 Cryptographically scrubbable storage device NATHAN GOODMAN, ROBERT MICHAEL PAWLOSKI, ALPHONSO A. SAMUEL 8471758 Virtual aperture radar (VAR) imaging CHARLES T. HANSEN 8451173 Maximum likelihood angle estimation of wideband signals using phased array antennas ALEXANDRA L. BLAKE, DAVID B. HATFIELD, NICHOLAS B. SACCKETTI, LAWRENCE A. WESTHOVEN JR., DARIN S. WILLIAMS, RICHARD J. WRIGHT 8461501 Guided munitions including self-deploying dome covers and methods for equipping guided munitions with the same STEVE E. HUETTNER 8451186 System and method for passive protection of an antenna feed network JONATHAN COMEAU, MATTHEW A. MORTON, EDWARD WADE THOENES 8461901 Harmonic reject mixer with active phase mismatch compensation in the local oscillator path LAWRENCE P. STRICKLAND 8452254 Selecting and routing sub-signals from a common signal path BARBARA J. BLYTH, RICHARD DELONG 8462042 Generating a kinematic indicator for combat identification classification JERRY HINSON 8452826 Digital frequency channelizer JAMES E. HARDIN, BENJAMIN PIERCE III, THOMAS P. ZAHM 8462861 Methods and apparatus for multipath mitigation MARIA ANTONIA ANDREWS,ROBERT B. BATIE, ALEN CRUZ, LUISITO D. ESPIRITU, STEPHAN GONZALEZ, SYLVIA A. TRAXLER 8453212 Accessing resources of a secure computing network MELVIN CAMPBELL, ETHAN S. HEINRICH, KEVIN C. ROLSTON, ROSALIO S. VIDAURRI, ALBERTO F. VISCARRA, DAVID T. WINSLOW 8453314 Process for forming channels in a flexible circuit substrate using an elongated wedge and a channel shaped receptacle JIMMY CLARK, MICHAEL DOAN, WILFRIED KRONE-SCHMIDT, DAVID LA KOMSKI, ALBERTO E. SCHROTH, CHRIS SHAFFER, STEPHEN SMITH, SHANNON WHITE 8453393 Encapsulated and vented particulate thermal insulation JAMES D. KUENEMAN, ANTON VANDERWYST 8453426 Current controlled field emission thruster RICHARD DRYER, CHRIS E. GESWENDER 8453572 Gun-fired propellant support assemblies and methods for same BUU DIEP, ROLAND GOOCH 8454789 Disposable bond gap control structures MICHAEL L. BREST, KENNETH L. MCALLISTER, RICHARD N. MULLINS 8455826 Variable aperture mechanism retention device GREG S. NEATH, JOHN W. ROSENVALL 8463612 Monitoring and collection of audio events MICHAEL R. JOHNSON, BRUCE E. PEOPLES, JONATHON P. SMITH 8463808 Expanding concept types in conceptual graphs JAMES F. KVIATKOFSKY, MARK A. NAMEY, JAMES R. TOPLICAR 8464949 Method and system for countering an incoming threat TIMOTHY J. IMHOLT 8465201 Electro-magnetic radiation detector RICHARD A. FUNK, DAVID J. KNAPP, CHADWICK B. MARTIN 8466407 Stray light baffles for a conformal dome with arch corrector optics MARTIN S. DENHAM 8466816 Method and apparatus for serializing bits JOSEPH J. ICHKHAN, DAVID A. ROCKWELL, JOHN H. SCHROEDER 8467426 Method and apparatus for cooling a fiber laser or amplifier GEORGE C. ADAMS, ELIZABETH M. BEGIN, SEANNA J. GITTLER, ARTHUR B. JOHNSON, KENRIC P. NELSON, SAMUEL H. ROSENTHAL, BRIAN J. SCANNELL, ERIC SCHEID, NORA T. TGAVALEKOS 8468111 Determining confidence of object identification DAVID L. JOHANSEN, DIANA J. KENNEDY, TOBY REED 8471905 Methods and apparatus for imaging MARK T. BUSCH, LACY G. COOK, IAN S. ROBINSON 8471915 Self-correcting adaptive long-stare electro-optical system HOWARD C. CHOE, DEWEY R. MYERS, CLIFFORD C. SAMMONS, LARRY R. SPLITTER, 8473929 Architecture tailoring system JAMES F. ASBROCK, JOHN E. CLEMENT, WILLIAM O. MCKEAG 8477291 System and method for ranging of targets JOHN BEDINGER, ROBERT B. HALLOCK, THOMAS E. KAZIOR, MICHAEL A. MOORE, KAMAL TABATABAIE RE44303 Passivation layer for a circuit device and method of manufacture International Patents Issued to Raytheon Titles are those on the U.S.-filed patents; actual titles on foreign counterparts are sometimes modified and not recorded. While we strive to list current international patents, many foreign patents issue much later than corresponding U.S. patents and may not yet be reflected. AUSTRALIA MARK E. BEHRENS, DANIEL A. COLICA, KENNETH W. VIRGIL 2007323898 Automated logistics support system incorporating a product integrity analysis system CHRISTOPHER J. GRAHAM, JOHN A. WHEELER, MATTHEW R. YEAGER 2008318929 Unmanned vehicle route management system RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 51 BRIAN A. ADAMS, CHRISTOPHER HECHT, JOHN A. WHEELER, MATTHEW R. YEAGER 2008318930 Unmanned vehicle simulation system JAMES W. CASALEGNO, MICHAEL F. JANIK, THOMAS MCHALE, KENNETH J. MCPHILLIPS, ARNOLD W. NOVICK, ILYA ROZENFELD, JOHN R. SHORT 2009222991 Autonomous sonar system and method CHARLES A. HALL, THEODORE N. TAHMISIAN JR. 2009241388 Small aperture interrogator antenna system employing sum difference azimuth discrimination techniques PETER R. DRAKE, YUCHOI F. LOK 2009244465 Methods and apparatus for detection/classification of radar targets including birds and other hazards K. BUELL, JIYUN C. IMHOLT, MATTHEW A. MORTON 2009300419 Multilayer metamaterial isolator CANADA SHANNON DAVIDSON, ROBERT J. PETERSON 2503773 System and method for computer cluster virtualization using dynamic boot images and virtual disk FRITZ STEUDEL 2532328 Process for phase-derived range measurements MARWAN KRUNZ, PHILLIP ROSENGARD 2539080 Encapsulating packets into a frame for a network QUENTON JONES, MARTIN STEVENS 2561774 Secondary radar message decoding VERNON R. GOODMAN, DAVID M. SHIFRIN, TIMOTHY R. HOLZHEIMER 2565775 Generating three-dimensional images using impulsive radio frequency signals GIB LEWIS 2580935 Overlapping subarray architecture JESSE GRATKE, MICHAEL F. JANIK, RYAN LEWIS, JAMES MILLER, THOMAS B. PEDERSON, JAMES H. ROONEY III, WILLIAM C. ZURAWSKI 2625683 Sonar system and method providing low probability of impact on marine mammals ANDREW B. FACCIANO, RICHARD A. MCCLAIN JR., ROBERT T. MOORE, CRAIG SEASLY, RAYMOND J. SPALL 2670325 Detachable aerodynamic missile stabilizing system CHINA CHRISTOPHER HIRSCHI, STEPHEN JACOBSEN, BRIAN MACLEAN, RALPH PENSEL 2007800461684 Conformable track assembly for a robotic crawler DAVID R. BISHOP, JERRY M. GRIMM, JAMES F. KVIATKOFSKY, GARY F. WAHLQUIST, KUANG YUH WU 2007800360753 Shaped ballistic radome STEPHEN JACOBSEN, MARC OLIVIER, RALPH PENSEL, FRASER M. SMITH 2008801029156 Serpentine robotic crawler having a continuous track EGYPT DANIEL FLOYD, DOUGLAS HALL 26080 Method and apparatuses for squelch break signaling device to provide session initiation protocol FRANCE CLARK DAVIS, STEPHEN JACOBSEN, MARC OLIVIER 1488087 Controllable combustion method and device GARY A. FRAZIER 1536562 Method and apparatus for generating a pulse of very narrow width ALEXANDER A. BETIN, KALIN SPARIOSU 1585202 Scalable laser with robust phase locking ROBERT P. ENZMANN, FRITZ STEUDEL, GEORGE THOME 1869492 System and method for coherently combining a plurality of radars MICHAEL B. SCHOBER 1902329 System and method for passively estimating angle and range of a source using signal samples collected simultaneously from a multi-aperture antenna JOHN BEDINGER, ROBERT B. HALLOCK, THOMAS E. KAZIOR, MICHAEL A. MOORE, KAMAL TABATABAIE 1956872 Environmental protection coating system and method EDWARD KITCHEN, DARIN S. WILLIAMS 1983485 FLIR-to-missile boresight correlation and non-uniformity compensation of the missile seeker ROBERT S. BRINKERHOFF, ROBERT CAVALLERI, JAMES M. COOK, RICHARD D. LOEHR, MICHAEL J. MAHNKEN 1991825 System and method for attitude control of a flight vehicle using pitch-over thrusters DEREK L. BUDISALICH, GEORGE D. BUDY, ERIK A. FJERSTAD 2002198 Methods and apparatus for integrated locked thruster mechanism CHARLES M. DE LAIR, CHRISTOPHER OWAN 2005036 Implicitly timed gear bearings JONATHAN LYNCH 2064777 Variable cross-coupling partial reflector and method MICHAEL BRENNAN, EDWARD DEZELICK, LUIS GIRALDO, BRETT GOLDSTEIN, MICHAEL MILLSPAUGH, JOHN RYAN, ROBERT WALLACE 2072190 Device and method for controlled breaching of reinforced concrete SOLOMON DE PICCIOTTO, BRADLEY D. KELLY 2074006 Method of determining a collision avoidance MAURICE J. HALMOS 2078968 Synthetic aperture ladar with chirped mode locked waveform STEPHEN JACOBSEN 2082159 Serpentine robotic crawler STEPHEN JACOBSEN 2008801044423 Pressure control valve having an asymetric valving structure STEPHEN JACOBSEN, MARC OLIVIER, RALPH PENSEL 2092265 Unmanned ground robotic vehicle having an alternatively extendible and retractable sensing appendage DENMARK KENNETH W. BROWN, JAMES R. GALLIVAN 2115711 Safeguard system for ensuring device operation in conformance with governing laws JONATHAN D. GORDON, REZA TAYRANI 2182632 Broadband microwave amplifier RODNEY J. CALLISON 2145206 Spotlight synthetic aperture radar (SAR) system and method for generating a SAR map in real-time using a modified polar format algorithm (PFA) approach LACY G. COOK, JOSHUA THORNES 2153498 Optical pulse-width modifier structure VETIS B. DAVIS, JOSE I. RODRIGUEZ 2167902 Method and apparatus for rapid mounting and dismounting of a firearm accessory JONATHAN D. GORDON, REZA TAYRANI 2182632 Broadband microwave amplifier WILLIAM P. HAROKOPUS, DARRELL W. MILLER 2214256 Composite radome and radiator structure PATRICK HOGAN, RALPH KORENSTEIN, JOHN MCCLOY, CHARLES WILLINGHAM JR. 2234936 Treatment method for optically transmissive bodies ROBERT CAVALLERI, THOMAS A. OLDEN 2245291 Pellet loaded attitude control rocket motor CRAIG BRADFORD, MARC A. BROWN, FRANK HITZKE, WILLIAM E. KOMM, MICHAEL W. LITTLE, DOMENIC F. NAPOLITANO, DAVID A. SHARP, DOUGLAS VEILLEUX II 2262676 Autonomous data relay buoy JAMES W. CASALEGNO, MICHAEL F. JANIK, THOMAS MCHALE, KENNETH J. MCPHILLIPS, ARNOLD W. NOVICK, ILYA ROZENFELD, JOHN R. SHORT 2263097 Autonomous sonar system and method RICHARD M. WEBER, WILLIAM G. WYATT 2274965 Cooling system for a computing rack CHARLES A. HALL, THEODORE N. TAHMISIAN JR. 2281324 Small aperture interrogator antenna system employing sum difference azimuth discrimination techniques INUKA D. DISSANAYAKE, DONALD M. HUGHES 2298039 Method and apparatus for an ionizer BRANDON H. ALLEN, KEVIN W. CHEN, WILLIAM P. HAROKOPUS, KERRIN A. RUMMEL, GARY L. SEIFERMAN, RICHARD M. WEBER 2313946 Heat removal system for a radome PAUL H. BARTON, RAYMOND R. BESHEARS, BERNARD D. HEER, CARL KIRKCONNELL, ROBERT R. OGDEN, BRADLEY A. ROSS 2326893 Monitoring the health of a cryocooler CHRIS E. GESWENDER, SHAWN B. HARLINE, NICHOLAS E. KOSINSKI 2335007 Projectile with filler material between fins and fuselage THOMAS K. DOUGHERTY, STEVEN E. LAU, CINDY W. MA, CHRISTOPHER T. SNIVELY, WILLIAM J. WOLFGONG 2356681 X-ray opaque coatings and application CARY C. KYHL 2388786 Temperature tolerant cover layer construction TERRY C. CISCO 2390954 Microwave directional coupler TERRY M. SANDERSON 2411673 Shape-change material and method LACY G. COOK 2418528 Pointable optical system with coude optics having a short on-gimbal path length LACY G. COOK, ERIC M. MOSKUN 2423726 Wide field of view LWIR high speed imager 52 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY DANIEL J. MOSIER, DAVID J. PARK 2427719 Method and system of aligning a track beam and a high energy laser beam JAMES T. SCHLEINING, MICHAEL P. UNGER, STEPHEN D. WITHERSPOON 2433084 Guided missile JOHN BEDINGER, ROBERT B. HALLOCK, THOMAS E. KAZIOR, MICHAEL A. MOORE, KAMAL TABATABAIE 2469993 Environmental protection coating system and method GERMANY ROBERT P. ENZMANN, FRITZ STEUDEL, GEORGE THOME 1869492 System and method for coherently combining a plurality of radars MICHAEL B. SCHOBER 1902329 System and method for passively estimating angle and range of a source using signal samples collected simultaneously from a multi-aperture antenna JOHN BEDINGER, ROBERT B. HALLOCK, THOMAS E. KAZIOR, MICHAEL A. MOORE, KAMAL TABATABAIE 1956872 Environmental protection coating system and method EDWARD KITCHEN, DARIN S. WILLIAMS 1983485 FLIR-to-missile boresight correlation and non-uniformity compensation of the missile seeker ROBERT S. BRINKERHOFF, ROBERT CAVALLERI, JAMES M. COOK, RICHARD D. LOEHR, MICHAEL J. MAHNKEN 1991825 System and method for attitude control of a flight vehicle using pitch-over thrusters DEREK L. BUDISALICH, GEORGE D. BUDY, ERIK A. FJERSTAD 2002198 Methods and apparatus for integrated locked thruster mechanism CHARLES M. DE LAIR, CHRISTOPHER OWAN 2005036 Implicitly timed gear bearings ROBERT CAVALLERI, THOMAS A. OLDEN 2245291 Pellet loaded attitude control rocket motor CAREY C. KYHL 6020110021079 Temperature tolerant cover layer construction CRAIG BRADFORD, MARC A. BROWN, FRANK HITZKE, WILLIAM E. KOMM, MICHAEL W. LITTLE, DOMENIC F. NAPOLITANO, DAVID A. SHARP, DOUGLAS VEILLEUX II 2262676 Autonomous data relay buoy CLARK DAVIS, STEPHEN JACOBSEN, MARC OLIVIER 603441165 Controllable combustion method and device CHARLES A. HALL, THEODORE N. TAHMISIAN JR. 2281324 Small aperture interrogator antenna system employing sum difference azimuth discrimination techniques INUKA D. DISSANAYAKE, DONALD M. HUGHES 2298039 Method and apparatus for an ionizer BRANDON H. ALLEN, KEVIN W. CHEN, WILLIAM P. HAROKOPUS, KERRIN A. RUMMEL, GARY L. SEIFERMAN, RICHARD M. WEBER 2313946 Heat removal system for a radome PAUL H. BARTON, RAYMOND R. BESHEARS, BERNARD D. HEER, CARL KIRKCONNELL, ROBERT R. OGDEN, BRADLEY A. ROSS 2326893 Monitoring the health of a cryocooler CHRIS E. GESWENDER, SHAWN B. HARLINE, NICHOLAS E. KOSINSKI 2335007 Projectile with filler material between fins and fuselage TERRY C. CISCO 2390954 Microwave directional coupler TERRY M. SANDERSON 2411673 Shape-change material and method LACY G. COOK 2418528 Pointable optical system with coude optics having a short on-gimbal path length JAMES T. SCHLEINING, MICHAEL P. UNGER, STEPHEN D. WITHERSPOON 2433084 Guided missile GREECE MICHAEL BRENNAN, EDWARD DEZELICK, LUIS GIRALDO, BRETT GOLDSTEIN, MICHAEL MILLSPAUGH, JOHN RYAN, ROBERT WALLACE 3080102 Device and method for controlled breaching of reinforced concrete HUNGARY DOUGLAS M. KAVNER 228601 System and method for reading license plates ISRAEL MICHAEL K. BURKLAND, DAVID B. HATFIELD, ELAINE E. SEASLY 174557 Molecular containment film modeling tool GERALD L. EHLERS, CHARLES LEPPLE, AARON WATTS 177660 Personal authentication device STEVEN COTTEN, BENJAMIN DOLGIN, MICHAEL SHORE 191589 Positioning system and method JAR J. LEE, STAN W. LIVINGSTON, CLIFTON QUAN 193821 Airship mounted array KENNETH GERBER, ROBERT GINN 195265 Method of construction of CTE matching structure with wafer processing and resulting structure FRANK N. CHEUNG 195990 Data translation system and method PATRICK M. KILGORE 196759 System and method for adaptive non-uniformity compensation for a focal plane array JAR J. LEE, STAN W. LIVINGSTON, CLIFTON QUAN 196879 Dual band space-fed array JOHN BEDINGER, ROBERT B. HALLOCK, THOMAS E. KAZIOR, MICHAEL A. MOORE, KAMAL TABATABAIE 2469993 Environmental protection coating system and method STEPHEN JACOBSEN 198710 Serpentine robotic crawler ALEXANDER A. BETIN, KALIN SPARIOSU 6020040411140 Scalable laser with robust phase locking CHRISTIAN HEMMI, JAMES MASON 199299 Polarization control method for phased arrays GARY A. FRAZIER 6020040421723 Method and apparatus for generating a pulse of very narrow width JOHN S. ANDERSON, CHUNGTE CHEN 199967 Common aperture optical system incorporating a light sensor and a light source JONATHAN D. GORDON, REZA TAYRANI 6020060340516 Broadband microwave amplifier LACY G. COOK, JOSHUA THORNES 201467 Optical pulse-width modifier structure MAURICE J. HALMOS 2078968 Synthetic aperture ladar with chirped mode locked waveform STEPHEN JACOBSEN 6020070297583 Serpentine robotic crawler PATRIC M. MCGUIRE 201560 Methods and apparatus for selecting a target from radar tracking data KENNETH W. BROWN, JAMES R. GALLIVAN 2115711 Safeguard system for ensuring device operation in conformance with governing laws STEPHEN JACOBSEN, MARC OLIVIER, RALPH PENSEL 6020070297621 Unmanned ground robotic vehicle having an alternatively extendible and retractable sensing appendage ITALY LACY G. COOK, JOSHUA THORNES 2153498 Optical pulse-width modifier structure THOMAS K. DOUGHERTY, STEVEN E. LAU, CINDY W. MA, CHRISTOPHER T. SNIVELY, WILLIAM J. WOLFGONG 6020090130323 X-ray opaque coatings and application JONATHAN LYNCH 2064777 Variable cross-coupling partial reflector and method MICHAEL BRENNAN, EDWARD DEZELICK, LUIS GIRALDO, BRETT GOLDSTEIN, MICHAEL MILLSPAUGH, JOHN RYAN, ROBERT WALLACE 2072190 Device and method for controlled breaching of reinforced concrete SOLOMON DE PICCIOTTO, BRADLEY D. KELLY 2074006 Method of determining a collision avoidance VETIS B. DAVIS, JOSE I. RODRIGUEZ 2167902 Method and apparatus for rapid mounting and dismounting of a firearm accessory RICHARD M. WEBER, WILLIAM G. WYATT 6020090138839 Cooling system for a computing rack WILLIAM P. HAROKOPUS, DARRELL W. MILLER 2214256 Composite radome and radiator structure DANIEL J. MOSIER, DAVID J. PARK 6020100066916 Method and system of aligning a track beam and a high energy laser beam PATRICK HOGAN, RALPH KORENSTEIN, JOHN MCCLOY, CHARLES WILLINGHAM JR. 2234936 Treatment method for optically transmissive bodies LACY G. COOK, ERIC M. MOSKUN 6020110013572 Wide field of view LWIR high speed imager ROBERT P. ENZMANN, FRITZ STEUDEL, GEORGE THOME 1869492 System and method for coherently combining a plurality of radars JOHN BEDINGER, ROBERT B. HALLOCK, THOMAS E. KAZIOR, MICHAEL A. MOORE, KAMAL TABATABAIE 1956872 Environmental protection coating system and method ROBERT S. BRINKERHOFF, ROBERT CAVALLERI, JAMES M. COOK, RICHARD D. LOEHR, MICHAEL J. MAHNKEN 1991825 System and method for attitude control of a flight vehicle using pitch-over thrusters RAYTHEON TECHNOLOGY TODAY 2014 ISSUE 1 53 MICHAEL BRENNAN, EDWARD DEZELICK, LUIS GIRALDO, BRETT GOLDSTEIN, MICHAEL MILLSPAUGH, JOHN RYAN, ROBERT WALLACE 2072190 Device and method for controlled breaching of reinforced concrete JONATHAN D. GORDON, REZA TAYRANI 2182632 Broadband microwave amplifier CRAIG BRADFORD, MARC A. BROWN, FRANK HITZKE, WILLIAM E. KOMM, MICHAEL W. LITTLE, DOMENIC F. NAPOLITANO, DAVID A. SHARP, DOUGLAS VEILLEUX II 2262676 Autonomous data relay buoy CHARLES A. HALL, THEODORE N. TAHMISIAN JR. 2281324 Small aperture interrogator antenna system employing sum difference azimuth discrimination techniques JOHN BEDINGER, ROBERT B. HALLOCK, THOMAS E. KAZIOR, MICHAEL A. MOORE, KAMAL TABATABAIE 2469993 Environmental protection coating system and method JAPAN REGINA ESTKOWSKI, PETER TINKER 5172326 System and method for adaptive path planning SCOTT R. CHEYNE, JEFFREY PAQUETTE 5181079 An electrical connector to connect circuit cards DAVID D. HESTON, JON MOONEY 5183199 Integrated circuit resistor JAMES BALLEW, SHANNON DAVIDSON 5184552 Computer storage system MICHAEL G. ADLERSTEIN, JOHN C. TREMBLAY 5192691 Radio frequency limiter circuit JAMES H. DUPONT, RICHARD D. LOEHR, WILLIAM N. PATTERSON 5242809 Buoyancy dissipator and method to deter an errant vessel PREMJEET CHAHAL, ATHANASIOS SYLLAIOS 5248771 Integrated spectroscopic microbolometer with microfilter arrays RANDY C. BARNHART, CRAIG S. KLOOSTERMAN, MELINDA C. MILANI, DONALD V. SCHNAIDT, STEVEN TALCOTT 5256019 Data handling in a distributed communication network JOHN SELIN 5259182 Quadrature offset power amplifier DAVID D. CROUCH, WILLIAM E. DOLASH, MICHAEL J. SOTELO 5259184 Multiple-port patch antenna ROBERT C. GIBBONS 5265332 Imaging system ROLAND TORRES 5272083 +28V aircraft transient suppression FRANCIS J. MORRIS 5279731 Method for fabricating electrical circuitry on ultra-thin plastic films ROBERT W. BYREN, DAVID SUMIDA, MICHAEL USHINSKY 5280998 Solid-state laser with spatially-tailored active ion concentration using valence conversion with surface masking and method STEPHEN JACOBSEN 5285701 Modular robotic crawler ARYEH PLATZKER, DOUGLAS TEETER 5198700 Transistor amplifier having reduced parasitic oscillations CHARLES A. HALL, THEODORE N. 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ROLSTON, FANGCHOU YANG 5221606 Multi-layer microwave corrugated printed circuit board and method STEPHEN JACOBSEN, MARC OLIVIER 5232177 Antagonistic fluid control system for active and passive actuator operation STEPHEN JACOBSEN 5232227 Pressure control valve having an assymetric valving structure JAMES BARGER, MARSHALL BRINN, STEPHEN D. MILLIGAN, RICHARD MULLEN 5232847 Systems and methods for disambiguating shooter locations DAVID CORKUM, MICHAEL K. HOLZ 5236853 Electronically variable light attenuator SOLOMON DE PICCIOTTO, BRADLEY D. KELLY 5237278 Method of determining a collision avoidance 54 2014 ISSUE 1 RAYTHEON TECHNOLOGY TODAY ARYEH PLATZKER, DOUGLAS TEETER 5296181 Transistor amplifier having reduced parasitic oscillations NETHERLANDS JONATHAN D. GORDON, REZA TAYRANI 2182632 Broadband microwave amplifier SOUTH KOREA (REPUBLIC OF KOREA) WILLIAM J. DAVIS, WARD G. FILLMORE, SCOTT MACDONALD 101219619 Method for packaging semiconductors at a wafer level KARL G. 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